Miscellaneous Utility Functions

Name

Miscellaneous Utility Functions -- a selection of portable utility functions.

Synopsis


#include <glib.h>


gchar*      g_get_prgname                   (void);
void        g_set_prgname                   (const gchar *prgname);
gchar*      g_getenv                        (const gchar *variable);
gchar*      g_get_user_name                 (void);
gchar*      g_get_real_name                 (void);

gchar*      g_get_home_dir                  (void);
gchar*      g_get_tmp_dir                   (void);
gchar*      g_get_current_dir               (void);
gchar*      g_basename                      (const gchar *file_name);
gchar*      g_dirname                       (const gchar *file_name);
gboolean    g_path_is_absolute              (const gchar *file_name);
gchar*      g_path_skip_root                (gchar *file_name);
gchar*      g_path_get_basename             (const gchar *file_name);
gchar*      g_path_get_dirname              (const gchar *file_name);

gchar*      g_find_program_in_path          (const gchar *program);

gint        g_bit_nth_lsf                   (guint32 mask,
                                             gint nth_bit);
gint        g_bit_nth_msf                   (guint32 mask,
                                             gint nth_bit);
guint       g_bit_storage                   (guint number);

guint       g_spaced_primes_closest         (guint num);

void        g_atexit                        (GVoidFunc func);

guint       g_parse_debug_string            (const gchar *string,
                                             GDebugKey *keys,
                                             guint nkeys);
struct      GDebugKey;

void        (*GVoidFunc)                    (void);
void        (*GFreeFunc)                    (gpointer data);

Description

These are portable utility functions.

Details

g_get_prgname ()

gchar*      g_get_prgname                   (void);

Gets the name of the program. (If you are using GDK or GTK the program name is set in gdk_init(), which is called by gtk_init(). The program name is found by taking the last component of argv[0].)

Returns :the name of the program.


g_set_prgname ()

void        g_set_prgname                   (const gchar *prgname);

Sets the name of the program.

prgname :the name of the program.


g_getenv ()

gchar*      g_getenv                        (const gchar *variable);

Returns an environment variable.

variable :the environment variable to get.
Returns :the value of the environment variable, or NULL if the environment variable is not found.


g_get_user_name ()

gchar*      g_get_user_name                 (void);

Gets the user name of the current user.

Returns :the user name of the current user.


g_get_real_name ()

gchar*      g_get_real_name                 (void);

Gets the real name of the user. This comes from the user's entry in the passwd file.

Returns :the user's real name.


g_get_home_dir ()

gchar*      g_get_home_dir                  (void);

Gets the current user's home directory.

Returns :the current user's home directory.


g_get_tmp_dir ()

gchar*      g_get_tmp_dir                   (void);

Gets the directory to use for temporary files. This is found from inspecting the environment variables TMPDIR, TMP, and TEMP in that order. If none of those are defined "/tmp" is returned.

Returns :the directory to use for temporary files.


g_get_current_dir ()

gchar*      g_get_current_dir               (void);

Gets the current directory. The returned string should be freed when no longer needed.

Returns :the current directory.


g_basename ()

gchar*      g_basename                      (const gchar *file_name);

This function is deprecated and will be removed in the next major release of GLib. Use g_path_get_basename() instead.

Gets the name of the file without any leading directory components. It returns a pointer into the given file name string.

file_name :the name of the file.
Returns :the name of the file without any leading directory components.


g_dirname ()

gchar*      g_dirname                       (const gchar *file_name);

This function is deprecated and will be removed in the next major release of GLib. Use g_path_get_dirname() instead.

Gets the directory components of a file name. If the file name has no directory components "." is returned. The returned string should be freed when no longer needed.

file_name :the name of the file.
Returns :the directory components of the file.


g_path_is_absolute ()

gboolean    g_path_is_absolute              (const gchar *file_name);

Returns TRUE if the given file_name is an absolute file name, i.e. it contains a full path from the root directory such as '/usr/local' or 'C:/windows' on windows systems.

file_name :a file name.
Returns :TRUE if file_name is an absolute path.


g_path_skip_root ()

gchar*      g_path_skip_root                (gchar *file_name);

Returns a pointer into file_name after the root component, i.e. after the '/' in Unix or 'C:/' under Windows. If file_name is not an absolute path it returns NULL.

file_name :a file name.
Returns :a pointer into file_name after the root component.


g_path_get_basename ()

gchar*      g_path_get_basename             (const gchar *file_name);

Gets the name of the file without any leading directory components. The returned string should be freed when no longer needed.

Note: This function allocates new memory for the returned string. This is different from the old g_basename() function, which returned a pointer into the argument.

file_name :the name of the file.
Returns :the name of the file without any leading directory components.


g_path_get_dirname ()

gchar*      g_path_get_dirname              (const gchar *file_name);

Gets the directory components of a file name. If the file name has no directory components "." is returned. The returned string should be freed when no longer needed.

file_name :the name of the file.
Returns :the directory components of the file.


g_find_program_in_path ()

gchar*      g_find_program_in_path          (const gchar *program);

Locates the first executable named program in the user's path, in the same way that execvp() would locate it. Returns an allocated string with the absolute path name, or NULL if the program is not found in the path. If program is already an absolute path, returns a copy of program if program exists and is executable, and NULL otherwise.

program : a program name
Returns : absolute path, or NULL


g_bit_nth_lsf ()

gint        g_bit_nth_lsf                   (guint32 mask,
                                             gint nth_bit);

Find the position of the first bit set in mask, searching from (but not including) nth_bit upwards. Bits are numbered from 0 (least significant) to 31. To start searching from the 0th bit, set nth_bit to -1.

mask :a guint32 containing up to 32 bit flags.
nth_bit :the index of the bit to start the search from.
Returns :the index of the first bit set which is higher than nth_bit.


g_bit_nth_msf ()

gint        g_bit_nth_msf                   (guint32 mask,
                                             gint nth_bit);

Find the position of the first bit set in mask, searching from (but not including) nth_bit downwards. Bits are numbered from 0 (least significant) to 31. To start searching from the 31st bit, set nth_bit to 32 or -1.

mask :a guint32 containing up to 32 bit flags.
nth_bit :the index of the bit to start the search from.
Returns :the index of the first bit set which is lower than nth_bit.


g_bit_storage ()

guint       g_bit_storage                   (guint number);

Gets the number of bits used to hold number, e.g. if number is 4, 3 bits are needed.

number :a guint.
Returns :the number of bits used to hold number.


g_spaced_primes_closest ()

guint       g_spaced_primes_closest         (guint num);

Gets the smallest prime number from a built-in array of primes which is larger than num. This is used within GLib to calculate the optimum size of a GHashTable.

The built-in array of primes ranges from 11 to 13845163 such that each prime is approximately 1.5-2 times the previous prime.

num :a guint.
Returns :the smallest prime number from a built-in array of primes which is larger than num.


g_atexit ()

void        g_atexit                        (GVoidFunc func);

Specifies a function to be called at normal program termination.

func :the function to call on normal program termination.


g_parse_debug_string ()

guint       g_parse_debug_string            (const gchar *string,
                                             GDebugKey *keys,
                                             guint nkeys);

Parses a string containing debugging options separated by ':' into a guint containing bit flags. This is used within GDK and GTK to parse the debug options passed on the command line or through environment variables.

string :a list of debug options separated by ':' or "all" to set all flags.
keys :pointer to an array of GDebugKey which associate strings with bit flags.
nkeys :the number of GDebugKey in the array.
Returns :the combined set of bit flags.


struct GDebugKey

struct GDebugKey
{
  gchar *key;
  guint	 value;
};

Associates a string with a bit flag. Used in g_parse_debug_string().


GVoidFunc ()

void        (*GVoidFunc)                    (void);

Declares a type of function which takes no arguments and has no return value. It is used to specify the type function passed to g_atexit().


GFreeFunc ()

void        (*GFreeFunc)                    (gpointer data);

Declares a type of function which takes an arbitrary data pointer argument and has no return value. It is not currently used in GLib or GTK+.

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