GLOB(3) | Library Functions Manual | GLOB(3) |
glob
, glob_b
,
globfree
— generate
pathnames matching a pattern
#include
<glob.h>
int
glob
(const
char * restrict pattern,
int flags,
int (*errfunc)(const char
*epath, int errno),
glob_t * restrict
pglob);
int
glob_b
(const
char * restrict pattern,
int flags,
int (^errblk)(const char
*epath, int errno),
glob_t * restrict
pglob);
void
globfree
(glob_t
*pglob);
The
glob
()
function is a pathname generator that implements the rules for file name
pattern matching used by the shell.
The include file
<glob.h>
defines the
structure type glob_t, which contains at least the
following fields:
typedef struct { size_t gl_pathc; /* count of total paths so far */ int gl_matchc; /* count of paths matching pattern */ size_t gl_offs; /* reserved at beginning of gl_pathv */ int gl_flags; /* returned flags */ char **gl_pathv; /* list of paths matching pattern */ } glob_t;
The argument pattern is a
pointer to a pathname pattern to be expanded. The
glob
()
argument matches all accessible pathnames against the pattern and creates a
list of the pathnames that match. In order to have access to a pathname,
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
special characters ‘*
’,
‘?
’ or
‘[
’.
The
glob
()
argument stores the number of matched pathnames into the
gl_pathc field, and a pointer to a list of pointers to
pathnames into the gl_pathv field. The first pointer
after the last pathname is NULL
. If the pattern does
not match any pathnames, the returned number of matched paths is set to
zero.
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 argument flags is used to
modify the behavior of
glob
(). The
value of flags is the bitwise inclusive OR of any of
the following values defined in
<glob.h>
:
GLOB_APPEND
glob
(). The value of
gl_pathc will be the total matches found by this
call and the previous call(s). The pathnames are appended to, not merged
with the pathnames returned by the previous call(s). Between calls, the
caller must not change the setting of the
GLOB_DOOFFS
flag, nor change the value of
gl_offs when GLOB_DOOFFS
is
set, nor (obviously) call globfree
() for
pglob.GLOB_DOOFFS
NULL
pointers to prepend to the beginning of the
gl_pathv field. In other words,
gl_pathv will point to gl_offs
NULL
pointers, followed by
gl_pathc pathname pointers, followed by a
NULL
pointer.GLOB_ERR
glob
() to return when it encounters a
directory that it cannot open or read. Ordinarily,
glob
() continues to find matches.GLOB_MARK
GLOB_NOCHECK
glob
() returns a list consisting of only
pattern, with the number of total pathnames set to
1, and the number of matched pathnames set to 0. The effect of backslash
escaping is present in the pattern returned.GLOB_NOESCAPE
\
’)
character is used to escape the following character in the pattern,
avoiding any special interpretation of the character. If
GLOB_NOESCAPE
is set, backslash escaping is
disabled.GLOB_NOSORT
glob
()).The following values may also be included in flags, however, they are non-standard extensions to IEEE Std 1003.2 (“POSIX.2”).
GLOB_ALTDIRFUNC
void *(*gl_opendir)(const char * name); struct dirent *(*gl_readdir)(void *); void (*gl_closedir)(void *); int (*gl_lstat)(const char *name, struct stat *st); int (*gl_stat)(const char *name, struct stat *st);
This extension is provided to allow programs such as restore(8) to provide globbing from directories stored on tape.
GLOB_BRACE
{pat,pat,...}
’ strings like
csh(1). The pattern
‘{}
’ is left unexpanded for
historical reasons (and csh(1) does the
same thing to ease typing of find(1)
patterns).GLOB_MAGCHAR
glob
()
function if the pattern included globbing characters. See the description
of the usage of the gl_matchc structure member for
more details.GLOB_NOMAGIC
GLOB_NOCHECK
but it only appends
the pattern if it does not contain any of the
special characters ``*'', ``?'' or ``[''.
GLOB_NOMAGIC
is provided to simplify implementing
the historic csh(1) globbing behavior
and should probably not be used anywhere else.GLOB_TILDE
~
’
to user name home directories.GLOB_LIMIT
ARG_MAX
).
This option should be set for programs that can be coerced into a denial
of service attack via patterns that expand to a very large number of
matches, such as a long string of
‘*/../*/..
’.If, during the search, a directory is encountered that
cannot be opened or read and errfunc is
non-NULL
,
glob
() calls
(*errfunc)(path,
errno). This may be unintuitive: a pattern like
‘*/Makefile
’ will try to
stat(2)
‘foo/Makefile
’ even if
‘foo
’ is not a directory, resulting in
a call to errfunc. The error routine can suppress this
action by testing for ENOENT
and
ENOTDIR
; however, the
GLOB_ERR
flag will still cause an immediate return
when this happens.
If errfunc returns non-zero,
glob
() stops
the scan and returns GLOB_ABORTED
after setting
gl_pathc and gl_pathv to reflect
any paths already matched. This also happens if an error is encountered and
GLOB_ERR
is set in flags,
regardless of the return value of errfunc, if called.
If GLOB_ERR
is not set and either
errfunc is NULL
or
errfunc returns zero, the error is ignored.
The
glob_b
()
function is like glob
() except that the error
callback is a block pointer instead of a function pointer.
The
globfree
()
function frees any space associated with pglob from a
previous call(s) to glob
() or
glob_b
().
On successful completion, glob
() and
glob_b
() return zero. In addition, the fields of
pglob contain the values described below:
glob
() or
glob_b
() if GLOB_APPEND
was specified.glob
() or glob_b
().GLOB_MAGCHAR
set if pattern
contained any of the special characters ``*'', ``?'' or ``['', cleared if
not.NULL
-terminated list of
matched pathnames. However, if gl_pathc is zero, the
contents of gl_pathv are undefined.If glob
() or
glob_b
() terminates due to an error, it sets errno
and returns one of the following non-zero constants, which are defined in
the include file
<glob.h>
:
GLOB_NOSPACE
GLOB_LIMIT
was specified in the flags
and pglob->gl_matchc or more patterns were
matched.GLOB_ABORTED
GLOB_ERR
was set or
(*errfunc)() returned non-zero.GLOB_NOMATCH
GLOB_NOCHECK
was not set.The arguments pglob->gl_pathc and pglob->gl_pathv are still set as specified above.
A rough equivalent of ‘ls -l *.c
*.h
’ can be obtained with the following code:
glob_t g; g.gl_offs = 2; glob("*.c", GLOB_DOOFFS, NULL, &g); glob("*.h", GLOB_DOOFFS | GLOB_APPEND, NULL, &g); g.gl_pathv[0] = "ls"; g.gl_pathv[1] = "-l"; execvp("ls", g.gl_pathv);
The glob
() and
glob_b
() functions will not match filenames that
begin with a period unless this is specifically requested (e.g., by
".*").
The current implementation of the glob
()
function does
not conform to IEEE Std 1003.2
(“POSIX.2”). Collating symbol expressions, equivalence
class expressions and character class expressions are not supported.
The flags GLOB_ALTDIRFUNC
,
GLOB_BRACE
, GLOB_LIMIT
,
GLOB_MAGCHAR
, GLOB_NOMAGIC
,
and GLOB_TILDE
, and the fields
gl_matchc and gl_flags are
extensions to the POSIX standard and should not be used by applications
striving for strict conformance.
The glob
() and
globfree
() functions first appeared in
4.4BSD. The glob_b
()
function first appeared in Mac OS X 10.6.
Patterns longer than MAXPATHLEN
may cause
unchecked errors.
The glob
() and
glob_b
() functions may fail and set errno for any of
the errors specified for the library routines
stat(2),
closedir(3),
opendir(3),
readdir(3),
malloc(3), and
free(3).
June 11, 2017 | macOS 14.6 |