int
glob(
const char * restrict pattern
, int flags
, const int (*errfunc)(const char *, int)
, glob_t * restrict pglob
)
void
globfree(
glob_t *pglob
)
)
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 */
size_t 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
).
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
gl_offs
field.
If this flag is set,
gl_offs
is used to specify how many
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
)
to return when it encounters a directory that it cannot open or read.
Ordinarily,
glob(
)
continues to find matches.
GLOB_MARK
pattern
has a slash
appended.
GLOB_NOCHECK
pattern
does not match any pathname, then
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.
GLOB_NOSORT
)).
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
GLOB_MAGCHAR
)
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_NOESCAPE
GLOB_TILDE
GLOB_LIMIT
64K
,
the number of
stat(2)
calls to 128, and the number of
readdir(3)
calls to 16K.
This option should be set for programs that can be coerced to a denial of
service attack via patterns that expand to a very large number of matches,
such as a long string of
*/../*/..
GLOB_PERIOD
GLOB_NO_DOTDIRS
.
'
and
`
..
'
from metacharacter matches, regardless of whether
GLOB_PERIOD
is set and whether the pattern component begins with a literal period.
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
globfree()
function frees any space associated with
pglob
from a previous call(s) to
glob().
The historical
GLOB_QUOTE
flag is no longer supported.
Per
IEEE Std 1003.2-1992 (``POSIX.2'') ,
backslash escaping of special characters is the default behaviour;
it may be disabled by specifying the
GLOB_NOESCAPE
flag.
)
returns zero.
In addition the fields of
pglob
contain the values described below:
gl_pathc
)
if
GLOB_APPEND
was specified.
gl_matchc
).
gl_flags
flags
parameter with the bit
GLOB_MAGCHAR
set if
pattern
contained any of the special characters ``*'', ``?'' or ``['', cleared
if not.
gl_pathv
NULL
-terminated
list of matched pathnames.
However, if
gl_pathc
is zero, the contents of
gl_pathv
are undefined.
If
glob()
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_ABORTED
GLOB_ERR
was set or
(*errfunc)()
returned non-zero.
GLOB_NOMATCH
GLOB_NOCHECK
was not set in
flags
.
GLOB_NOSPACE
GLOB_LIMIT
was specified in the flags and
ARG_MAX
patterns were matched.
The historical
GLOB_ABEND
return constant is no longer supported.
Portable applications should use the
GLOB_ABORTED
constant instead.
The arguments
pglob->gl_pathc
and
pglob->gl_pathv
are still set as specified above.
HOME
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);
)
function is expected to be
IEEE Std 1003.2 (``POSIX.2'')
compatible with the exception
that the flags
GLOB_ALTDIRFUNC
,
GLOB_BRACE
,
GLOB_MAGCHAR
,
GLOB_NOMAGIC
,
GLOB_TILDE
,
and
GLOB_LIMIT
and the fields
gl_matchc
and
gl_flags
should not be used by applications striving for strict
POSIX
conformance.
)
and
globfree(
)
functions first appeared in
4.4BSD.
MAXPATHLEN
may cause unchecked errors.
The
glob()
function 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).