Content-type: text/html Man page of glob

glob

Section: C Library Functions (3)
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NAME

glob, globfree - Generate pathnames matching a pattern  

LIBRARY

Standard C Library (libc.so, libc.a)  

SYNOPSIS

#include <glob.h>

int glob(
        const char *pattern,
        int flags,
        int (*errfunc)(const char *epath, int eerrno),
        glob_t *pglob);

void globfree(
        glob_t *pglob);  

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

glob(), globfree():  XPG4, XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.  

PARAMETERS

Contains the filename pattern to compare against accessible pathnames. Controls the customizable behavior of the glob function. Specifies an optional function that, if specified, is called when the glob() function detects an error condition. Contains a pointer to a glob_t structure. The structure is allocated by the caller. The array of structures containing the filenames located that match the pattern parameter are stored by the glob() function into the structure. The last entry is a NULL pointer. Contains the pathname that failed because a directory could not be opened or read. Specifies the errno value from a failure specified by the epath parameter, as set by the opendir(), readdir(), or stat() functions.  

DESCRIPTION

The glob() function constructs a list of accessible files that match the pattern parameter.

The glob() function matches all accessible pathnames against this pattern and develops a list of all pathnames that match. In order to have access to a pathname, the glob() function requires search permission on every component of a pathname except the last, and read permission on each directory of any filename component of the pattern parameter that contains any of the special characters * (asterisk), ? (question mark), or [ (open bracket).

The glob() function stores the number of matched pathnames and a pointer to a list of pointers to pathnames in the pglob parameter. The pathnames are sorted, based on the setting of the LC_COLLATE category in the current locale. The first pointer after the last pathname is NULL. If the pattern does not match any pathnames, the returned number of matched pathnames is 0 (zero).

It is the caller's responsibility to create the structure pointed to by the pglob parameter. The glob function allocates other space as needed. The globfree() function frees any space associated with the pglob parameter due to a previous call to the glob() function.

The flags parameter is used to control the behavior of the glob() function. The flags value is the bitwise inclusive OR (|) of any of the following constants, which are defined in the glob.h file. Appends pathnames located with this call to any pathnames previously located. Uses the gl_offs structure to specify the number of NULL pointers to add to the beginning of the gl_pathv component of the pglob parameter. Causes the glob() function to return when it encounters a directory that it cannot open or read. If the GLOB_ERR flag is not set, the glob() function continues to find matches if it encounters a directory that it cannot open or read. Specifies that each pathname that is a directory should have a / (slash) appended. If the pattern parameter does not match any pathname, then the glob() function returns a list consisting only of the pattern parameter, and the number of matched patterns is one. If the GLOB_NOESCAPE flag is set, a \ (backslash) cannot be used to escape metacharacters. Specifies that the list of pathnames need not be sorted. If the GLOB_NOSORT flag is not set, pathnames are collated according to the current setting of the LC_COLLATE category.

The GLOB_APPEND flag can be used to append a new set of pathnames to those found in a previous call to the glob() function. The following rules apply when two or more calls to the glob() function are made with the same value of the pglob parameter and without intervening calls to the glob() function: If the application set the GLOB_DOOFFS flag in the first call to the glob() function, then it is also set in the second call, and the value of the gl_ofs field of the pglob parameter is not modified between the calls. If the application did not set the GLOB_DOOFFS flag in the first call to the glob() function, then it is not set in the second call. After the second call, the gl_pattr field of the pglob parameter points to a list containing the following: Zero or more NULLs, as specified by the GLOB_DOOFFS flag and pglob->gl_offs. Pointers to the pathnames that were in the pglob->gl_pathv list before the call, in the same order as after the first call to the glob() function. Pointers to the new pathnames generated by the second call, in the specified order. The count returned in the pglob->gl_pathc parameter is the total number of pathnames from the two calls. The application should not modify the pglob->gl_pathc or pglob->gl_pathv fields between the two calls.  

EXAMPLES

Note that the pglob parameter has meaning even if the glob() function fails. This allows the glob() function to report partial results in the event of an error. However, if the number of matched pathnames is 0 (zero), the pointer in the pglob parameter is unspecified even if the glob() function did not return an error.

The GLOB_NOCHECK flag can be used when an application wants to expand a pathname if wildcards are specified, but wants to treat the pattern as just a string otherwise. The sh command can use this for flag parameters, for example.

One use of the GLOB_DOOFFS flag is for applications that build an argument list for use with the execv(), execve(), or execvp() functions; for example, if an application needs to do the equivalent of ls -l *.c, but for some reason this 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 approximated using the GLOB_APPEND flag as follows:

globbuf.gl_offs = 2; glob ("*.c", GLOB_DOOFFS, NULL, &globbuf); glob ("*.h", GLOB_DOOFFS|GLOB_APPEND, NULL, &globbuf);

The new pathnames generated by a subsequent call with the GLOB_APPEND flag set are not sorted together with the previous pathnames. This process mirrors the way that the shell handles pathname expansion when multiple expansions are done on a command line.  

RETURN VALUES

On successful completion, the glob() function returns a value of 0 (zero). The pglob->gl_pathc field returns the number of matched pathnames and the pglob->gl_pathv field contains a pointer to a NULL-terminated list of matched and sorted pathnames. If the number of matched pathnames in the pglob->gl_pathc parameter is 0 (zero), the pointer in the pglob->gl_pathv parameter is undefined.

If the glob() function terminates due to an error, the function returns one of the following nonzero constants. These are defined in the glob.h file. In this case, the pglob parameter values are still set as defined above. Indicates the scan was stopped because GLOB_ERROR was set or errfunc returned a nonzero value. Indicates the pattern does not match any existing pathname, and GLOB_NOCHECK was not set in flags. Indicates an attempt to allocate memory failed.

If, during the search, a directory is encountered that cannot be opened or read and the errfunc parameter value is not NULL, the glob() function calls errfunc with two arguments: Specifies the pathname that failed. Specifies the value of errno from the failure, as set by the opendir(), readdir(), or stat() functions.

If errfunc is called and returns nonzero, or if the GLOB_ERR flag is set in flags, the glob() function stops the scan and returns GLOB_ABORTED after setting the pglob parameter to reflect the pathnames already scanned. If GLOB_ERR is not set and either errfunc is NULL or errfunc returns zero, the error is ignored.

No errno values are returned.  

FILES

Defines glob() macros, data types, and functions.  

RELATED INFORMATION

Functions: fnmatch(3), opendir(3), readdir(3), stat(2)

Standards: standards(5) delim off


 

Index

NAME
LIBRARY
SYNOPSIS
STANDARDS
PARAMETERS
DESCRIPTION
EXAMPLES
RETURN VALUES
FILES
RELATED INFORMATION

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Time: 02:41:50 GMT, October 02, 2010