path: root/man3/glob.3

.\" (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
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.\" Modified Wed Jul 28 11:12:17 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified Mon May 13 23:08:50 1996 by Martin Schulze (joey@linux.de)
.\" Modified 11 May 1998 by Joseph S. Myers (jsm28@cam.ac.uk)
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.\"
.TH GLOB 3  1999-09-12 "GNU" "Linux Programmer's Manual"
.SH NAME
glob, globfree \- find pathnames matching a pattern, free memory from glob()
.SH SYNOPSIS
.nf
.B #include <glob.h>
.sp
.BI "int glob(const char *" pattern ", int " flags ,
.nl
.BI "         int " errfunc "(const char *" epath ", int " eerrno ),
.nl
.BI "         glob_t *" pglob );
.nl
.BI "void globfree(glob_t *" pglob );
.fi
.SH DESCRIPTION
The
.B glob()
function searches for all the pathnames matching
.I pattern
according to the rules used by the shell (see
.BR glob (7)).
No tilde expansion or parameter substitution is done; if you want
these, use
.BR wordexp (3).
.PP
The
.B globfree()
function frees the dynamically allocated storage from an earlier call
to
.BR glob() .
.PP
The results of a
.B glob()
call are stored in the structure pointed to by
.IR pglob ,
which is a
.B glob_t
which is declared in
.B <glob.h>
and includes the following elements defined by POSIX.2 (more may be
present as an extension):
.PP
.br
.nf
.in 10
typedef struct
{
.in 14
    size_t gl_pathc;    /* Count of paths matched so far  */
    char **gl_pathv;    /* List of matched pathnames.  */
    size_t gl_offs;     /* Slots to reserve in `gl_pathv'.  */
.in 10
} glob_t;
.fi
.PP
Results are stored in dynamically allocated storage.
.PP
The parameter
.I flags
is made up of bitwise OR of zero or more the following symbolic
constants, which modify the of behaviour of
.BR glob() :
.TP
.B GLOB_ERR
which means to return upon read error (because a directory does not
have read permission, for example),
.TP
.B GLOB_MARK
which means to append a slash to each path which corresponds to a directory,
.TP
.B GLOB_NOSORT
which means don't sort the returned pathnames (they are by default),
.TP
.B GLOB_DOOFFS
which means that
.I pglob->gl_offs
slots will be reserved at the beginning of the list of strings in
.IR pglob->pathv ,
.TP
.B GLOB_NOCHECK
which means that, if no pattern matches, to return the original pattern,
.TP
.B GLOB_APPEND
which means to append to the results of a previous call.  Do not set
this flag on the first invocation of
.BR glob() .
.TP
.B GLOB_NOESCAPE
which means that meta characters cannot be quoted by backslashes.
.PP
The flags may also include some of the following, which are GNU
extensions and not defined by POSIX.2:
.TP
.B GLOB_PERIOD
which means that a leading period can be matched by meta characters,
.TP
.B GLOB_ALTDIRFUNC
which means that alternative functions
.IR pglob->gl_closedir ,
.IR pglob->gl_readdir ,
.IR pglob->gl_opendir ,
.IR pglob->gl_lstat ", and"
.I pglob->gl_stat
are used for file system access instead of the normal library
functions,
.TP
.B GLOB_BRACE
which means that
.BR csh (1)
style brace expresions \fB{a,b}\fR are expanded,
.TP
.B GLOB_NOMAGIC
which means that the pattern is returned if it contains no metacharacters,
.TP
.B GLOB_TILDE
which means that tilde expansion is carried out, and
.TP
.B GLOB_ONLYDIR
which means that only directories are matched.
.PP
If
.I errfunc
is not
.BR NULL ,
it will be called in case of an error with the arguments
.IR epath ,
a pointer to the path which failed, and
.IR eerrno ,
the value of
.I errno
as returned from one of the calls to
.BR opendir() ", " readdir() ", or " stat() .
If 
.I errfunc
returns non-zero, or if
.B GLOB_ERR
is set, 
.B glob()
will terminate after the call to
.IR errfunc .
.PP
Upon successful return, 
.I pglob->gl_pathc
contains the number of matched pathnames and
.I pglob->gl_pathv
a pointer to the list of matched pathnames.  The first pointer after
the last pathname is
.BR NULL .
.PP
It is possible to call
.B glob()
several times.  In that case, the
.B GLOB_APPEND
flag has to be set in
.I flags
on the second and later invocations.
.PP
As a GNU extension,
.I pglob->gl_flags
is set to the flags specified, \fBor\fRed with
.B GLOB_MAGCHAR
if any metacharacters were found.
.SH "RETURN VALUE"
On successful completion, 
.B glob()
returns zero.
Other possible returns are:
.TP
.B GLOB_NOSPACE
for running out of memory,
.TP
.B GLOB_ABORTED
for a read error, and
.TP
.B GLOB_NOMATCH
for no found matches.
.SH EXAMPLES
One example of use is the following code, which simulates typing
.nl
.B ls -l *.c ../*.c
.nl
in the shell.
.nf
.in 10

glob_t globbuf;

globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &globbuf);
glob("../*.c", GLOB_DOOFFS | GLOB_APPEND, NULL, &globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp("ls", &globbuf.gl_pathv[0]);
.fi
.SH "CONFORMING TO"
POSIX.2
.SH BUGS
The
.B glob()
function may fail due to failure of underlying function calls, such as
.BR malloc() " or " opendir() .
These will store their error code in
.IR errno .
.SH NOTES
The structure elements
.I gl_pathc
and
.I gl_offs
are declared as
.BR size_t
in glibc 2.1, as they should according to POSIX.2,
but are declared as
.B int
in libc4, libc5 and glibc 2.0.
.SH "SEE ALSO"
.BR ls (1),
.BR sh (1),
.BR stat (2),
.BR exec (3),
.BR malloc (3),
.BR opendir (3),
.BR readdir (3),
.BR wordexp (3),
.BR glob (7)