Synopsis


#include <glib.h>
#include <glib/gprintf.h>


gchar*      g_strdup                        (const gchar *str);
gchar*      g_strndup                       (const gchar *str,
                                             gsize n);
gchar**     g_strdupv                       (gchar **str_array);
gchar*      g_strnfill                      (gsize length,
                                             gchar fill_char);
gchar*      g_stpcpy                        (gchar *dest,
                                             const char *src);
gchar*      g_strstr_len                    (const gchar *haystack,
                                             gssize haystack_len,
                                             const gchar *needle);
gchar*      g_strrstr                       (const gchar *haystack,
                                             const gchar *needle);
gchar*      g_strrstr_len                   (const gchar *haystack,
                                             gssize haystack_len,
                                             const gchar *needle);
gboolean    g_str_has_prefix                (const gchar *str,
                                             const gchar *prefix);
gboolean    g_str_has_suffix                (const gchar *str,
                                             const gchar *suffix);

gsize       g_strlcpy                       (gchar *dest,
                                             const gchar *src,
                                             gsize dest_size);
gsize       g_strlcat                       (gchar *dest,
                                             const gchar *src,
                                             gsize dest_size);

gchar*      g_strdup_printf                 (const gchar *format,
                                             ...);
gchar*      g_strdup_vprintf                (const gchar *format,
                                             va_list args);
gint        g_printf                        (gchar const *format,
                                             ...);
gint        g_vprintf                       (gchar const *format,
                                             va_list args);
gint        g_fprintf                       (FILE *file,
                                             gchar const *format,
                                             ...);
gint        g_vfprintf                      (FILE *file,
                                             gchar const *format,
                                             va_list args);
gint        g_sprintf                       (gchar *string,
                                             gchar const *format,
                                             ...);
gint        g_vsprintf                      (gchar *string,
                                             gchar const *format,
                                             va_list args);
gint        g_snprintf                      (gchar *string,
                                             gulong n,
                                             gchar const *format,
                                             ...);
gint        g_vsnprintf                     (gchar *string,
                                             gulong n,
                                             gchar const *format,
                                             va_list args);
gint        g_vasprintf                     (gchar **string,
                                             gchar const *format,
                                             va_list args);
gsize       g_printf_string_upper_bound     (const gchar *format,
                                             va_list args);

gboolean    g_ascii_isalnum                 (gchar c);
gboolean    g_ascii_isalpha                 (gchar c);
gboolean    g_ascii_iscntrl                 (gchar c);
gboolean    g_ascii_isdigit                 (gchar c);
gboolean    g_ascii_isgraph                 (gchar c);
gboolean    g_ascii_islower                 (gchar c);
gboolean    g_ascii_isprint                 (gchar c);
gboolean    g_ascii_ispunct                 (gchar c);
gboolean    g_ascii_isspace                 (gchar c);
gboolean    g_ascii_isupper                 (gchar c);
gboolean    g_ascii_isxdigit                (gchar c);

gint        g_ascii_digit_value             (gchar c);
gint        g_ascii_xdigit_value            (gchar c);

gint        g_ascii_strcasecmp              (const gchar *s1,
                                             const gchar *s2);
gint        g_ascii_strncasecmp             (const gchar *s1,
                                             const gchar *s2,
                                             gsize n);

gchar*      g_ascii_strup                   (const gchar *str,
                                             gssize len);
gchar*      g_ascii_strdown                 (const gchar *str,
                                             gssize len);

gchar       g_ascii_tolower                 (gchar c);
gchar       g_ascii_toupper                 (gchar c);

GString*    g_string_ascii_up               (GString *string);
GString*    g_string_ascii_down             (GString *string);

gchar*      g_strup                         (gchar *string);
gchar*      g_strdown                       (gchar *string);

gint        g_strcasecmp                    (const gchar *s1,
                                             const gchar *s2);
gint        g_strncasecmp                   (const gchar *s1,
                                             const gchar *s2,
                                             guint n);

gchar*      g_strreverse                    (gchar *string);

gint64      g_ascii_strtoll                 (const gchar *nptr,
                                             gchar **endptr,
                                             guint base);
guint64     g_ascii_strtoull                (const gchar *nptr,
                                             gchar **endptr,
                                             guint base);
#define     G_ASCII_DTOSTR_BUF_SIZE
gdouble     g_ascii_strtod                  (const gchar *nptr,
                                             gchar **endptr);
gchar*      g_ascii_dtostr                  (gchar *buffer,
                                             gint buf_len,
                                             gdouble d);
gchar*      g_ascii_formatd                 (gchar *buffer,
                                             gint buf_len,
                                             const gchar *format,
                                             gdouble d);
gdouble     g_strtod                        (const gchar *nptr,
                                             gchar **endptr);

gchar*      g_strchug                       (gchar *string);
gchar*      g_strchomp                      (gchar *string);
#define     g_strstrip                      ( string )

gchar*      g_strdelimit                    (gchar *string,
                                             const gchar *delimiters,
                                             gchar new_delimiter);
#define     G_STR_DELIMITERS
gchar*      g_strescape                     (const gchar *source,
                                             const gchar *exceptions);
gchar*      g_strcompress                   (const gchar *source);
gchar*      g_strcanon                      (gchar *string,
                                             const gchar *valid_chars,
                                             gchar substitutor);
gchar**     g_strsplit                      (const gchar *string,
                                             const gchar *delimiter,
                                             gint max_tokens);
gchar**     g_strsplit_set                  (const gchar *string,
                                             const gchar *delimiters,
                                             gint max_tokens);
void        g_strfreev                      (gchar **str_array);
gchar*      g_strconcat                     (const gchar *string1,
                                             ...);
gchar*      g_strjoin                       (const gchar *separator,
                                             ...);
gchar*      g_strjoinv                      (const gchar *separator,
                                             gchar **str_array);
guint       g_strv_length                   (gchar **str_array);

const gchar* g_strerror                     (gint errnum);
const gchar* g_strsignal                    (gint signum);

Description

This section describes a number of utility functions for creating, duplicating, and manipulating strings.

Note that the functions g_printf(), g_fprintf(), g_sprintf(), g_snprintf(), g_vprintf(), g_vfprintf(), g_vsprintf() and g_vsnprintf() are declared in the header gprintf.h which is not included in glib.h (otherwise using glib.h would drag in stdio.h), so you'll have to explicitly include <glib/gprintf.h> in order to use the GLib printf() functions.

While you may use the printf() functions to format UTF-8 strings, notice that the precision of a %Ns parameter is interpreted as the number of bytes, not characters to print. On top of that, the GNU libc implementation of the printf() functions has the "feature" that it checks that the string given for the %Ns parameter consists of a whole number of characters in the current encoding. So, unless you are sure you are always going to be in an UTF-8 locale or your know your text is restricted to ASCII, avoid using %Ns. If your intention is to format strings for a certain number of columns, then %Ns is not a correct solution anyway, since it fails to take wide characters (see g_unichar_iswide()) into account.

Details

g_strdup ()

gchar*      g_strdup                        (const gchar *str);

Duplicates a string. If str is NULL it returns NULL. The returned string should be freed when no longer needed.

str : the string to duplicate.
Returns : a newly-allocated copy of str.

g_strndup ()

gchar*      g_strndup                       (const gchar *str,
                                             gsize n);

Duplicates the first n characters of a string, returning a newly-allocated buffer n + 1 characters long which will always be nul-terminated. If str is less than n characters long the buffer is padded with nuls. If str is NULL it returns NULL. The returned value should be freed when no longer needed.

str : the string to duplicate part of.
n : the maximum number of characters to copy from str.
Returns : a newly-allocated buffer containing the first n characters of str, nul-terminated.

g_strdupv ()

gchar**     g_strdupv                       (gchar **str_array);

Copies NULL-terminated array of strings. The copy is a deep copy; the new array should be freed by first freeing each string, then the array itself. g_strfreev() does this for you. If called on a NULL value, g_strdupv() simply returns NULL.

str_array : NULL-terminated array of strings.
Returns : a new NULL-terminated array of strings.

g_strnfill ()

gchar*      g_strnfill                      (gsize length,
                                             gchar fill_char);

Creates a new string length characters long filled with fill_char. The returned string should be freed when no longer needed.

length : the length of the new string.
fill_char : the character to fill the string with.
Returns : a newly-allocated string filled the fill_char.

g_stpcpy ()

gchar*      g_stpcpy                        (gchar *dest,
                                             const char *src);

Copies a nul-terminated string into the dest buffer, include the trailing nul, and return a pointer to the trailing nul byte. This is useful for concatenating multiple strings together without having to repeatedly scan for the end.

dest : destination buffer.
src : source string.
Returns : a pointer to trailing nul byte.

g_strstr_len ()

gchar*      g_strstr_len                    (const gchar *haystack,
                                             gssize haystack_len,
                                             const gchar *needle);

Searches the string haystack for the first occurrence of the string needle, limiting the length of the search to haystack_len.

haystack : a string.
haystack_len : the maximum length of haystack.
needle : the string to search for.
Returns : a pointer to the found occurrence, or NULL if not found.

g_strrstr ()

gchar*      g_strrstr                       (const gchar *haystack,
                                             const gchar *needle);

Searches the string haystack for the last occurrence of the string needle.

haystack : a nul-terminated string.
needle : the nul-terminated string to search for.
Returns : a pointer to the found occurrence, or NULL if not found.

g_strrstr_len ()

gchar*      g_strrstr_len                   (const gchar *haystack,
                                             gssize haystack_len,
                                             const gchar *needle);

Searches the string haystack for the last occurrence of the string needle, limiting the length of the search to haystack_len.

haystack : a nul-terminated string.
haystack_len : the maximum length of haystack.
needle : the nul-terminated string to search for.
Returns : a pointer to the found occurrence, or NULL if not found.

g_str_has_prefix ()

gboolean    g_str_has_prefix                (const gchar *str,
                                             const gchar *prefix);

Looks whether the string str begins with prefix.

str : a nul-terminated string.
prefix : the nul-terminated prefix to look for.
Returns : TRUE if str begins with prefix, FALSE otherwise.

Since 2.2


g_str_has_suffix ()

gboolean    g_str_has_suffix                (const gchar *str,
                                             const gchar *suffix);

Looks whether the string str ends with suffix.

str : a nul-terminated string.
suffix : the nul-terminated suffix to look for.
Returns : TRUE if str end with suffix, FALSE otherwise.

Since 2.2


g_strlcpy ()

gsize       g_strlcpy                       (gchar *dest,
                                             const gchar *src,
                                             gsize dest_size);

Portability wrapper that calls strlcpy() on systems which have it, and emulates strlcpy() otherwise. Copies src to dest; dest is guaranteed to be nul-terminated; src must be nul-terminated; dest_size is the buffer size, not the number of chars to copy. Caveat: strlcpy() is supposedly more secure than strcpy() or strncpy(), but if you really want to avoid screwups, g_strdup() is an even better idea.

dest : destination buffer
src : source buffer
dest_size : length of dest in bytes
Returns : length of src

g_strlcat ()

gsize       g_strlcat                       (gchar *dest,
                                             const gchar *src,
                                             gsize dest_size);

Portability wrapper that calls strlcat() on systems which have it, and emulates it otherwise. Appends nul-terminated src string to dest, guaranteeing nul-termination for dest. The total size of dest won't exceed dest_size. Caveat: this is supposedly a more secure alternative to strcat() or strncat(), but for real security g_strconcat() is harder to mess up.

dest : destination buffer, already containing one nul-terminated string
src : source buffer
dest_size : length of dest buffer in bytes (not length of existing string inside dest)
Returns : length of src plus initial length of string in dest

g_strdup_printf ()

gchar*      g_strdup_printf                 (const gchar *format,
                                             ...);

Similar to the standard C sprintf() function but safer, since it calculates the maximum space required and allocates memory to hold the result. The returned string should be freed when no longer needed.

format : a standard printf() format string, but notice string precision pitfalls.
... : the parameters to insert into the format string.
Returns : a newly-allocated string holding the result.

g_strdup_vprintf ()

gchar*      g_strdup_vprintf                (const gchar *format,
                                             va_list args);

Similar to the standard C vsprintf() function but safer, since it calculates the maximum space required and allocates memory to hold the result. The returned string should be freed when no longer needed.

See also g_vasprintf(), which offers the same functionality, but additionally returns the length of the allocated string.

format : a standard printf() format string, but notice string precision pitfalls.
args : the list of parameters to insert into the format string.
Returns : a newly-allocated string holding the result.

g_printf ()

gint        g_printf                        (gchar const *format,
                                             ...);

An implementation of the standard printf() function which supports positional parameters, as specified in the Single Unix Specification.

format : a standard printf() format string, but notice string precision pitfalls.
... : the arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_vprintf ()

gint        g_vprintf                       (gchar const *format,
                                             va_list args);

An implementation of the standard vprintf() function which supports positional parameters, as specified in the Single Unix Specification.

format : a standard printf() format string, but notice string precision pitfalls.
args : the list of arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_fprintf ()

gint        g_fprintf                       (FILE *file,
                                             gchar const *format,
                                             ...);

An implementation of the standard fprintf() function which supports positional parameters, as specified in the Single Unix Specification.

file : the stream to write to.
format : a standard printf() format string, but notice string precision pitfalls.
... : the arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_vfprintf ()

gint        g_vfprintf                      (FILE *file,
                                             gchar const *format,
                                             va_list args);

An implementation of the standard fprintf() function which supports positional parameters, as specified in the Single Unix Specification.

file : the stream to write to.
format : a standard printf() format string, but notice string precision pitfalls.
args : the list of arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_sprintf ()

gint        g_sprintf                       (gchar *string,
                                             gchar const *format,
                                             ...);

An implementation of the standard sprintf() function which supports positional parameters, as specified in the Single Unix Specification.

string : the buffer to hold the output.
format : a standard printf() format string, but notice string precision pitfalls.
... : the arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_vsprintf ()

gint        g_vsprintf                      (gchar *string,
                                             gchar const *format,
                                             va_list args);

An implementation of the standard vsprintf() function which supports positional parameters, as specified in the Single Unix Specification.

string : the buffer to hold the output.
format : a standard printf() format string, but notice string precision pitfalls.
args : the list of arguments to insert in the output.
Returns : the number of characters printed.

Since 2.2


g_snprintf ()

gint        g_snprintf                      (gchar *string,
                                             gulong n,
                                             gchar const *format,
                                             ...);

A safer form of the standard sprintf() function. The output is guaranteed to not exceed n characters (including the terminating nul character), so it is easy to ensure that a buffer overflow cannot occur.

See also g_strdup_printf().

In versions of GLib prior to 1.2.3, this function may return -1 if the output was truncated, and the truncated string may not be nul-terminated. In versions prior to 1.3.12, this function returns the length of the output string.

The return value of g_snprintf() conforms to the snprintf() function as standardized in ISO C99. Note that this is different from traditional snprintf(), which returns the length of the output string.

The format string may contain positional parameters, as specified in the Single Unix Specification.

string : the buffer to hold the output.
n : the maximum number of characters to produce (including the terminating nul character).
format : a standard printf() format string, but notice string precision pitfalls.
... : the arguments to insert in the output.
Returns : the number of characters which would be produced if the buffer was large enough.

g_vsnprintf ()

gint        g_vsnprintf                     (gchar *string,
                                             gulong n,
                                             gchar const *format,
                                             va_list args);

A safer form of the standard vsprintf() function. The output is guaranteed to not exceed n characters (including the terminating nul character), so it is easy to ensure that a buffer overflow cannot occur.

See also g_strdup_vprintf().

In versions of GLib prior to 1.2.3, this function may return -1 if the output was truncated, and the truncated string may not be nul-terminated. In versions prior to 1.3.12, this function returns the length of the output string.

The return value of g_vsnprintf() conforms to the vsnprintf() function as standardized in ISO C99. Note that this is different from traditional vsnprintf(), which returns the length of the output string.

The format string may contain positional parameters, as specified in the Single Unix Specification.

string : the buffer to hold the output.
n : the maximum number of characters to produce (including the terminating nul character).
format : a standard printf() format string, but notice string precision pitfalls.
args : the list of arguments to insert in the output.
Returns : the number of characters which would be produced if the buffer was large enough.

g_vasprintf ()

gint        g_vasprintf                     (gchar **string,
                                             gchar const *format,
                                             va_list args);

An implementation of the GNU vasprintf() function which supports positional parameters, as specified in the Single Unix Specification. This function is similar to g_vsprintf(), except that it allocates a string to hold the output, instead of putting the output in a buffer you allocate in advance.

string : the return location for the newly-allocated string.
format : a standard printf() format string, but notice string precision pitfalls.
args : the list of arguments to insert in the output.
Returns : the number of characters printed.

Since 2.4


g_printf_string_upper_bound ()

gsize       g_printf_string_upper_bound     (const gchar *format,
                                             va_list args);

Calculates the maximum space needed to store the output of the sprintf() function.

format : the format string. See the printf() documentation.
args : the parameters to be inserted into the format string.
Returns : the maximum space needed to store the formatted string.

g_ascii_isalnum ()

gboolean    g_ascii_isalnum                 (gchar c);

Determines whether a character is alphanumeric.

Unlike the standard C library isalnum() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII alphanumeric character

g_ascii_isalpha ()

gboolean    g_ascii_isalpha                 (gchar c);

Determines whether a character is alphabetic (i.e. a letter).

Unlike the standard C library isalpha() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII alphabetic character

g_ascii_iscntrl ()

gboolean    g_ascii_iscntrl                 (gchar c);

Determines whether a character is a control character.

Unlike the standard C library iscntrl() function, this only recognizes standard ASCII control characters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII control character.

g_ascii_isdigit ()

gboolean    g_ascii_isdigit                 (gchar c);

Determines whether a character is digit (0-9).

Unlike the standard C library isdigit() function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII digit.

g_ascii_isgraph ()

gboolean    g_ascii_isgraph                 (gchar c);

Determines whether a character is a printing character and not a space.

Unlike the standard C library isgraph() function, this only recognizes standard ASCII characters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII printing character other than space.

g_ascii_islower ()

gboolean    g_ascii_islower                 (gchar c);

Determines whether a character is an ASCII lower case letter.

Unlike the standard C library islower() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to worry about casting to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII lower case letter

g_ascii_isprint ()

gboolean    g_ascii_isprint                 (gchar c);

Determines whether a character is a printing character.

Unlike the standard C library isprint() function, this only recognizes standard ASCII characters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII printing character.

g_ascii_ispunct ()

gboolean    g_ascii_ispunct                 (gchar c);

Determines whether a character is a punctuation character.

Unlike the standard C library ispunct() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII punctuation character.

g_ascii_isspace ()

gboolean    g_ascii_isspace                 (gchar c);

Determines whether a character is a white-space character.

Unlike the standard C library isspace() function, this only recognizes standard ASCII white-space and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII white-space character

g_ascii_isupper ()

gboolean    g_ascii_isupper                 (gchar c);

Determines whether a character is an ASCII upper case letter.

Unlike the standard C library isupper() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to worry about casting to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII upper case letter

g_ascii_isxdigit ()

gboolean    g_ascii_isxdigit                (gchar c);

Determines whether a character is a hexadecimal-digit character.

Unlike the standard C library isxdigit() function, this takes a char, not an int, so don't call it on EOF but no need to cast to guchar before passing a possibly non-ASCII character in.

c : any character
Returns : TRUE if c is an ASCII hexadecimal-digit character.

g_ascii_digit_value ()

gint        g_ascii_digit_value             (gchar c);

Determines the numeric value of a character as a decimal digit. Differs from g_unichar_digit_value() because it takes a char, so there's no worry about sign extension if characters are signed.

c : an ASCII character.
Returns : If c is a decimal digit (according to g_ascii_isdigit()), its numeric value. Otherwise, -1.

g_ascii_xdigit_value ()

gint        g_ascii_xdigit_value            (gchar c);

Determines the numeric value of a character as a hexidecimal digit. Differs from g_unichar_xdigit_value() because it takes a char, so there's no worry about sign extension if characters are signed.

c : an ASCII character.
Returns : If c is a hex digit (according to g_ascii_isxdigit()), its numeric value. Otherwise, -1.

g_ascii_strcasecmp ()

gint        g_ascii_strcasecmp              (const gchar *s1,
                                             const gchar *s2);

Compare two strings, ignoring the case of ASCII characters.

Unlike the BSD strcasecmp() function, this only recognizes standard ASCII letters and ignores the locale, treating all non-ASCII bytes as if they are not letters.

This function should be used only on strings that are known to be in encodings where the bytes corresponding to ASCII letters always represent themselves. This includes UTF-8 and the ISO-8859-* charsets, but not for instance double-byte encodings like the Windows Codepage 932, where the trailing bytes of double-byte characters include all ASCII letters. If you compare two CP932 strings using this function, you will get false matches.

s1 : string to compare with s2.
s2 : string to compare with s1.
Returns : 0 if the strings match, a negative value if s1 < s2, or a positive value if s1 > s2.

g_ascii_strncasecmp ()

gint        g_ascii_strncasecmp             (const gchar *s1,
                                             const gchar *s2,
                                             gsize n);

Compare s1 and s2, ignoring the case of ASCII characters and any characters after the first n in each string.

Unlike the BSD strcasecmp() function, this only recognizes standard ASCII letters and ignores the locale, treating all non-ASCII characters as if they are not letters.

The same warning as in g_ascii_strcasecmp() applies: Use this function only on strings known to be in encodings where bytes corresponding to ASCII letters always represent themselves.

s1 : string to compare with s2.
s2 : string to compare with s1.
n : number of characters to compare.
Returns : 0 if the strings match, a negative value if s1 < s2, or a positive value if s1 > s2.

g_ascii_strup ()

gchar*      g_ascii_strup                   (const gchar *str,
                                             gssize len);

Converts all lower case ASCII letters to upper case ASCII letters.

str : a string.
len : length of str in bytes, or -1 if str is nul-terminated.
Returns : a newly allocated string, with all the lower case characters in str converted to upper case, with semantics that exactly match g_ascii_toupper(). (Note that this is unlike the old g_strup(), which modified the string in place.)

g_ascii_strdown ()

gchar*      g_ascii_strdown                 (const gchar *str,
                                             gssize len);

Converts all upper case ASCII letters to lower case ASCII letters.

str : a string.
len : length of str in bytes, or -1 if str is nul-terminated.
Returns : a newly-allocated string, with all the upper case characters in str converted to lower case, with semantics that exactly match g_ascii_tolower(). (Note that this is unlike the old g_strdown(), which modified the string in place.)

g_ascii_tolower ()

gchar       g_ascii_tolower                 (gchar c);

Convert a character to ASCII lower case.

Unlike the standard C library tolower() function, this only recognizes standard ASCII letters and ignores the locale, returning all non-ASCII characters unchanged, even if they are lower case letters in a particular character set. Also unlike the standard library function, this takes and returns a char, not an int, so don't call it on EOF but no need to worry about casting to guchar before passing a possibly non-ASCII character in.

c : any character.
Returns : the result of converting c to lower case. If c is not an ASCII upper case letter, c is returned unchanged.

g_ascii_toupper ()

gchar       g_ascii_toupper                 (gchar c);

Convert a character to ASCII upper case.

Unlike the standard C library toupper() function, this only recognizes standard ASCII letters and ignores the locale, returning all non-ASCII characters unchanged, even if they are upper case letters in a particular character set. Also unlike the standard library function, this takes and returns a char, not an int, so don't call it on EOF but no need to worry about casting to guchar before passing a possibly non-ASCII character in.

c : any character.
Returns : the result of converting c to upper case. If c is not an ASCII lower case letter, c is returned unchanged.

g_string_ascii_up ()

GString*    g_string_ascii_up               (GString *string);

Converts all lower case ASCII letters to upper case ASCII letters.

string : a GString
Returns : passed-in string pointer, with all the lower case characters converted to upper case in place, with semantics that exactly match g_ascii_toupper.

g_string_ascii_down ()

GString*    g_string_ascii_down             (GString *string);

Converts all upper case ASCII letters to lower case ASCII letters.

string : a GString
Returns : passed-in string pointer, with all the upper case characters converted to lower case in place, with semantics that exactly match g_ascii_tolower.

g_strup ()

gchar*      g_strup                         (gchar *string);

Warning

g_strup has been deprecated since version 2.2 and should not be used in newly-written code. This function is totally broken for the reasons discussed in the g_strncasecmp() docs - use g_ascii_strup() or g_utf8_strup() instead.

Converts a string to upper case.

string : the string to convert.
Returns : the string

g_strdown ()

gchar*      g_strdown                       (gchar *string);

Warning

g_strdown has been deprecated since version 2.2 and should not be used in newly-written code. This function is totally broken for the reasons discussed in the g_strncasecmp() docs - use g_ascii_strdown() or g_utf8_strdown() instead.

Converts a string to lower case.

string : the string to convert.
Returns : the string

g_strcasecmp ()

gint        g_strcasecmp                    (const gchar *s1,
                                             const gchar *s2);

Warning

g_strcasecmp has been deprecated since version 2.2 and should not be used in newly-written code. See g_strncasecmp() for a discussion of why this function is deprecated and how to replace it.

A case-insensitive string comparison, corresponding to the standard strcasecmp() function on platforms which support it.

s1 : a string.
s2 : a string to compare with s1.
Returns : 0 if the strings match, a negative value if s1 < s2, or a positive value if s1 > s2.

g_strncasecmp ()

gint        g_strncasecmp                   (const gchar *s1,
                                             const gchar *s2,
                                             guint n);

Warning

g_strncasecmp has been deprecated since version 2.2 and should not be used in newly-written code. The problem with g_strncasecmp() is that it does the comparison by calling toupper()/tolower(). These functions are locale-specific and operate on single bytes. However, it is impossible to handle things correctly from an I18N standpoint by operating on bytes, since characters may be multibyte. Thus g_strncasecmp() is broken if your string is guaranteed to be ASCII, since it's locale-sensitive, and it's broken if your string is localized, since it doesn't work on many encodings at all, including UTF-8, EUC-JP, etc.

There are therefore two replacement functions: g_ascii_strncasecmp(), which only works on ASCII and is not locale-sensitive, and g_utf8_casefold(), which is good for case-insensitive sorting of UTF-8.

A case-insensitive string comparison, corresponding to the standard strncasecmp() function on platforms which support it. It is similar to g_strcasecmp() except it only compares the first n characters of the strings.

s1 : a string.
s2 : a string to compare with s1.
n : the maximum number of characters to compare.
Returns : 0 if the strings match, a negative value if s1 < s2, or a positive value if s1 > s2.

g_strreverse ()

gchar*      g_strreverse                    (gchar *string);

Reverses all of the bytes in a string. For example, g_strreverse ("abcdef") will result in "fedcba".

Note that g_strreverse() doesn't work on UTF-8 strings containing multibyte characters. For that purpose, use g_utf8_strreverse().

string : the string to reverse.
Returns : the same pointer passed in as string.

g_ascii_strtoll ()

gint64      g_ascii_strtoll                 (const gchar *nptr,
                                             gchar **endptr,
                                             guint base);

Converts a string to a gint64 value. This function behaves like the standard strtoll() function does in the C locale. It does this without actually changing the current locale, since that would not be thread-safe.

This function is typically used when reading configuration files or other non-user input that should be locale independent. To handle input from the user you should normally use the locale-sensitive system strtoll() function.

If the correct value would cause overflow, G_MAXINT64 or G_MININT64 is returned, and ERANGE is stored in errno. If the base is outside the valid range, zero is returned, and EINVAL is stored in errno. If the string conversion fails, zero is returned, and endptr returns nptr (if endptr is non-NULL).

nptr : the string to convert to a numeric value.
endptr : if non-NULL, it returns the character after the last character used in the conversion.
base : to be used for the conversion, 2..36 or 0
Returns : the gint64 value or zero on error.

Since 2.12


g_ascii_strtoull ()

guint64     g_ascii_strtoull                (const gchar *nptr,
                                             gchar **endptr,
                                             guint base);

Converts a string to a guint64 value. This function behaves like the standard strtoull() function does in the C locale. It does this without actually changing the current locale, since that would not be thread-safe.

This function is typically used when reading configuration files or other non-user input that should be locale independent. To handle input from the user you should normally use the locale-sensitive system strtoull() function.

If the correct value would cause overflow, G_MAXUINT64 is returned, and ERANGE is stored in errno. If the base is outside the valid range, zero is returned, and EINVAL is stored in errno. If the string conversion fails, zero is returned, and endptr returns nptr (if endptr is non-NULL).

nptr : the string to convert to a numeric value.
endptr : if non-NULL, it returns the character after the last character used in the conversion.
base : to be used for the conversion, 2..36 or 0
Returns : the guint64 value or zero on error.

Since 2.2


G_ASCII_DTOSTR_BUF_SIZE

#define G_ASCII_DTOSTR_BUF_SIZE (29 + 10)

A good size for a buffer to be passed into g_ascii_dtostr(). It is guaranteed to be enough for all output of that function on systems with 64bit IEEE-compatible doubles.

The typical usage would be something like:

  char buf[G_ASCII_DTOSTR_BUF_SIZE];

  fprintf (out, "value=%s\n", g_ascii_dtostr (buf, sizeof (buf), value));


g_ascii_strtod ()

gdouble     g_ascii_strtod                  (const gchar *nptr,
                                             gchar **endptr);

Converts a string to a gdouble value. This function behaves like the standard strtod() function does in the C locale. It does this without actually changing the current locale, since that would not be thread-safe.

This function is typically used when reading configuration files or other non-user input that should be locale independent. To handle input from the user you should normally use the locale-sensitive system strtod() function.

To convert from a gdouble to a string in a locale-insensitive way, use g_ascii_dtostr().

If the correct value would cause overflow, plus or minus HUGE_VAL is returned (according to the sign of the value), and ERANGE is stored in errno. If the correct value would cause underflow, zero is returned and ERANGE is stored in errno.

This function resets errno before calling strtod() so that you can reliably detect overflow and underflow.

nptr : the string to convert to a numeric value.
endptr : if non-NULL, it returns the character after the last character used in the conversion.
Returns : the gdouble value.

g_ascii_dtostr ()

gchar*      g_ascii_dtostr                  (gchar *buffer,
                                             gint buf_len,
                                             gdouble d);

Converts a gdouble to a string, using the '.' as decimal point.

This functions generates enough precision that converting the string back using g_ascii_strtod() gives the same machine-number (on machines with IEEE compatible 64bit doubles). It is guaranteed that the size of the resulting string will never be larger than G_ASCII_DTOSTR_BUF_SIZE bytes.

buffer : A buffer to place the resulting string in
buf_len : The length of the buffer.
d : The gdouble to convert
Returns : The pointer to the buffer with the converted string.

g_ascii_formatd ()

gchar*      g_ascii_formatd                 (gchar *buffer,
                                             gint buf_len,
                                             const gchar *format,
                                             gdouble d);

Converts a gdouble to a string, using the '.' as decimal point. To format the number you pass in a printf()-style format string. Allowed conversion specifiers are 'e', 'E', 'f', 'F', 'g' and 'G'.

If you just want to want to serialize the value into a string, use g_ascii_dtostr().

buffer : A buffer to place the resulting string in
buf_len : The length of the buffer.
format : The printf()-style format to use for the code to use for converting.
d : The gdouble to convert
Returns : The pointer to the buffer with the converted string.

g_strtod ()

gdouble     g_strtod                        (const gchar *nptr,
                                             gchar **endptr);

Converts a string to a gdouble value. It calls the standard strtod() function to handle the conversion, but if the string is not completely converted it attempts the conversion again with g_ascii_strtod(), and returns the best match.

This function should seldomly be used. The normal situation when reading numbers not for human consumption is to use g_ascii_strtod(). Only when you know that you must expect both locale formatted and C formatted numbers should you use this. Make sure that you don't pass strings such as comma separated lists of values, since the commas may be interpreted as a decimal point in some locales, causing unexpected results.

nptr : the string to convert to a numeric value.
endptr : if non-NULL, it returns the character after the last character used in the conversion.
Returns : the gdouble value.

g_strchug ()

gchar*      g_strchug                       (gchar *string);

Removes leading whitespace from a string, by moving the rest of the characters forward.

This function doesn't allocate or reallocate any memory; it modifies string in place. The pointer to string is returned to allow the nesting of functions.

Also see g_strchomp() and g_strstrip().

string : a string to remove the leading whitespace from.
Returns : string.

g_strchomp ()

gchar*      g_strchomp                      (gchar *string);

Removes trailing whitespace from a string.

This function doesn't allocate or reallocate any memory; it modifies string in place. The pointer to string is returned to allow the nesting of functions.

Also see g_strchug() and g_strstrip().

string : a string to remove the trailing whitespace from.
Returns : string.

g_strstrip()

#define     g_strstrip( string )

Removes leading and trailing whitespace from a string. See g_strchomp() and g_strchug().

string : a string to remove the leading and trailing whitespace from.

g_strdelimit ()

gchar*      g_strdelimit                    (gchar *string,
                                             const gchar *delimiters,
                                             gchar new_delimiter);

Converts any delimiter characters in string to new_delimiter. Any characters in string which are found in delimiters are changed to the new_delimiter character. Modifies string in place, and returns string itself, not a copy. The return value is to allow nesting such as g_ascii_strup (g_strdelimit (str, "abc", '?')).

string : the string to convert.
delimiters : a string containing the current delimiters, or NULL to use the standard delimiters defined in G_STR_DELIMITERS.
new_delimiter : the new delimiter character.
Returns : string.

G_STR_DELIMITERS

#define	 G_STR_DELIMITERS	"_-|> <."

The standard delimiters, used in g_strdelimit().


g_strescape ()

gchar*      g_strescape                     (const gchar *source,
                                             const gchar *exceptions);

Escapes the special characters '\b', '\f', '\n', '\r', '\t', '\' and '"' in the string source by inserting a '\' before them. Additionally all characters in the range 0x01-0x1F (everything below SPACE) and in the range 0x7F-0xFF (all non-ASCII chars) are replaced with a '\' followed by their octal representation. Characters supplied in exceptions are not escaped.

g_strcompress() does the reverse conversion.

source : a string to escape.
exceptions : a string of characters not to escape in source.
Returns : a newly-allocated copy of source with certain characters escaped. See above.

g_strcompress ()

gchar*      g_strcompress                   (const gchar *source);

Replaces all escaped characters with their one byte equivalent. It does the reverse conversion of g_strescape().

source : a string to compress.
Returns : a newly-allocated copy of source with all escaped character compressed.

g_strcanon ()

gchar*      g_strcanon                      (gchar *string,
                                             const gchar *valid_chars,
                                             gchar substitutor);

For each character in string, if the character is not in valid_chars, replaces the character with substitutor. Modifies string in place, and return string itself, not a copy. The return value is to allow nesting such as g_ascii_strup (g_strcanon (str, "abc", '?')).

string : a nul-terminated array of bytes.
valid_chars : bytes permitted in string.
substitutor : replacement character for disallowed bytes.
Returns : string.

g_strsplit ()

gchar**     g_strsplit                      (const gchar *string,
                                             const gchar *delimiter,
                                             gint max_tokens);

Splits a string into a maximum of max_tokens pieces, using the given delimiter. If max_tokens is reached, the remainder of string is appended to the last token.

As a special case, the result of splitting the empty string "" is an empty vector, not a vector containing a single string. The reason for this special case is that being able to represent a empty vector is typically more useful than consistent handling of empty elements. If you do need to represent empty elements, you'll need to check for the empty string before calling g_strsplit().

string : a string to split.
delimiter : a string which specifies the places at which to split the string. The delimiter is not included in any of the resulting strings, unless max_tokens is reached.
max_tokens : the maximum number of pieces to split string into. If this is less than 1, the string is split completely.
Returns : a newly-allocated NULL-terminated array of strings. Use g_strfreev() to free it.

g_strsplit_set ()

gchar**     g_strsplit_set                  (const gchar *string,
                                             const gchar *delimiters,
                                             gint max_tokens);

Splits string into a number of tokens not containing any of the characters in delimiter. A token is the (possibly empty) longest string that does not contain any of the characters in delimiters. If max_tokens is reached, the remainder is appended to the last token.

For example the result of g_strsplit_set ("abc:def/ghi", ":/", -1) is a NULL-terminated vector containing the three strings "abc", "def", and "ghi".

The result if g_strsplit_set (":def/ghi:", ":/", -1) is a NULL-terminated vector containing the four strings "", "def", "ghi", and "".

As a special case, the result of splitting the empty string "" is an empty vector, not a vector containing a single string. The reason for this special case is that being able to represent a empty vector is typically more useful than consistent handling of empty elements. If you do need to represent empty elements, you'll need to check for the empty string before calling g_strsplit_set().

Note that this function works on bytes not characters, so it can't be used to delimit UTF-8 strings for anything but ASCII characters.

string : The string to be tokenized
delimiters : A nul-terminated string containing bytes that are used to split the string.
max_tokens : The maximum number of tokens to split string into. If this is less than 1, the string is split completely
Returns : a newly-allocated NULL-terminated array of strings. Use g_strfreev() to free it.

Since 2.4


g_strfreev ()

void        g_strfreev                      (gchar **str_array);

Frees a NULL-terminated array of strings, and the array itself. If called on a NULL value, g_strfreev() simply returns.

str_array : a NULL-terminated array of strings to free.

g_strconcat ()

gchar*      g_strconcat                     (const gchar *string1,
                                             ...);

Concatenates all of the given strings into one long string. The returned string should be freed when no longer needed.

Warning

The variable argument list must end with NULL. If you forget the NULL, g_strconcat() will start appending random memory junk to your string.

string1 : The first string to add, which must not be NULL.
... : a NULL-terminated list of strings to append to the string.
Returns : a newly-allocated string containing all the string arguments.

g_strjoin ()

gchar*      g_strjoin                       (const gchar *separator,
                                             ...);

Joins a number of strings together to form one long string, with the optional separator inserted between each of them.

separator : a string to insert between each of the strings, or NULL.
... : a NULL-terminated list of strings to join.
Returns : a newly-allocated string containing all of the strings joined together, with separator between them.

g_strjoinv ()

gchar*      g_strjoinv                      (const gchar *separator,
                                             gchar **str_array);

Joins a number of strings together to form one long string, with the optional separator inserted between each of them.

separator : a string to insert between each of the strings, or NULL.
str_array : a NULL-terminated array of strings to join.
Returns : a newly-allocated string containing all of the strings joined together, with separator between them.

g_strv_length ()

guint       g_strv_length                   (gchar **str_array);

Returns the length of the given NULL-terminated string array str_array.

str_array : a NULL-terminated array of strings.
Returns : length of str_array.

Since 2.6


g_strerror ()

const gchar* g_strerror                     (gint errnum);

Returns a string corresponding to the given error code, e.g. "no such process". This function is included since not all platforms support the strerror() function.

errnum : the system error number. See the standard C errno documentation.
Returns : a string describing the error code. If the error code is unknown, it returns "unknown error (<code>)". The string can only be used until the next call to g_strerror().

g_strsignal ()

const gchar* g_strsignal                    (gint signum);

Returns a string describing the given signal, e.g. "Segmentation fault". This function is included since not all platforms support the strsignal() function.

signum : the signal number. See the signal documentation.
Returns : a string describing the signal. If the signal is unknown, it returns "unknown signal (<signum>)". The string can only be used until the next call to g_strsignal().