Партнёры:
Хостинг:
glob, globfree - generate path names matching a pattern
#include <glob.h>
int glob(const char *restrict pattern, int flags,
int(*errfunc)(const char *epath, int eerrno),
glob_t *restrict pglob);
void globfree(glob_t *pglob);
The glob() function is a path name generator.
The globfree() function frees any memory allocated by glob() associated with pglob.
The argument pattern is a pointer to a path name pattern to be expanded. The glob() function matches all accessible path names against this pattern and develops a list of all path names that match. In order to have access to a path name, glob() requires search permission on every component of a path except the last, and read permission on each directory of any filename component of pattern that contains any of the following special characters:
* ? [
The structure type glob_t is defined in the header <glob.h> and includes at least the following members:
size_t gl_pathc; /* count of paths matched by */
/* pattern */
char **gl_pathv; /* pointer to list of matched */
/* path names */
size_t gl_offs; /* slots to reserve at beginning */
/* of gl_pathv */
The glob() function stores the number of matched path names into pglob->gl_pathc and a pointer to a list of pointers to path names into pglob->gl_pathv. The path names are in sort order as defined by the current setting of the LC_COLLATE category. The first pointer after the last path name is a NULL pointer. If the pattern does not match any path names, the returned number of matched paths is set to 0, and the contents of pglob->gl_pathv are implementation-dependent.
It is the caller's responsibility to create the structure pointed to by pglob. The glob() function allocates other space as needed, including the memory pointed to by gl_pathv. The globfree() function frees any space associated with pglob from a previous call to glob().
The flags argument is used to control the behavior of glob(). The value of flags is a bitwise inclusive OR of zero or more of the following constants, which are defined in the header <glob.h>:
GLOB_APPEND
GLOB_DOOFFS
GLOB_ERR
GLOB_MARK
GLOB_NOCHECK
GLOB_NOESCAPE
GLOB_NOSORT
The GLOB_APPEND flag can be used to append a new set of path names to those found in a previous call to glob(). The following rules apply when two or more calls to glob() are made with the same value of pglob and without intervening calls to globfree():
If, during the search, a directory is encountered that cannot be opened or read and errfunc is not a NULL pointer, glob() calls (*errfunc) with two arguments:
The following constants are defined as error return values for glob():
GLOB_ABORTED
GLOB_NOMATCH
GLOG_NOSPACE
If (*errfunc) is called and returns non-zero, or if the GLOB_ERR flag is set in flags, glob() stops the scan and returns GLOB_ABORTED after setting gl_pathc and gl_pathv in pglob to reflect the paths already scanned. If GLOB_ERR is not set and either errfunc is a NULL pointer or (*errfunc) returns 0, the error is ignored.
The following values are returned by glob():
0
non-zero
The globfree() function returns no value.
This function is not provided for the purpose of enabling utilities to perform path name expansion on their arguments, as this operation is performed by the shell, and utilities are explicitly not expected to redo this. Instead, it is provided for applications that need to do path name expansion on strings obtained from other sources, such as a pattern typed by a user or read from a file.
If a utility needs to see if a path name matches a given pattern, it can use fnmatch(3C).
Note that gl_pathc and gl_pathv have meaning even if glob() fails. This allows glob() to report partial results in the event of an error. However, if gl_pathc is 0, gl_pathv is unspecified even if glob() did not return an error.
The GLOB_NOCHECK option could be used when an application wants to expand a path name if wildcards are specified, but wants to treat the pattern as just a string otherwise.
The new path names generated by a subsequent call with GLOB_APPEND are not sorted together with the previous path names. This mirrors the way that the shell handles path name expansion when multiple expansions are done on a command line.
Applications that need tilde and parameter expansion should use the wordexp(3C) function.
Example 1 Example of glob_doofs function.
One use of the GLOB_DOOFFS flag is by applications that build an argument list for use with the execv(), execve(), or execvp() functions (see exec(2)). Suppose, for example, that an application wants to do the equivalent of:
ls -l *.c
but for some reason:
system("ls -l *.c")
is not acceptable. The application could obtain approximately the same result using the sequence:
globbuf.gl_offs = 2;
glob ("*.c", GLOB_DOOFFS, NULL, &globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp ("ls", &globbuf.gl_pathv[0]);
Using the same example:
ls -l *.c *.h
could be approximately simulated using GLOB_APPEND as follows:
globbuf.gl_offs = 2;
glob ("*.c", GLOB_DOOFFS, NULL, &globbuf);
glob ("*.h", GLOB_DOOFFS|GLOB_APPEND, NULL, &globbuf);
...
See attributes(5) for descriptions of the following attributes:
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execv(2), stat(2), fnmatch(3C), opendir(3C), readdir(3C), wordexp(3C), attributes(5), standards(5)
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