GLOB
Section: C Library Functions (3)
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NAME
glob
globfree
- generate pathnames matching a pattern
SYNOPSIS
Fd #include <glob.h>
Ft int
Fn glob const char *pattern int flags const int (*errfunc)(const char *, int) glob_t *pglob
Ft void
Fn globfree glob_t *pglob
DESCRIPTION
The
Fn 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
Fa glob_t ,
which contains at least the following fields:
typedef struct {
int gl_pathc; /* count of total paths so far */
int gl_matchc; /* count of paths matching pattern */
int 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
Fa pattern
is a pointer to a pathname pattern to be expanded.
The
Fn 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,
Fn glob
requires search permission on every component of a path except the last
and read permission on each directory of any filename component of
Fa pattern
that contains any of the special characters
`*'
,
`?'
or
`['
The
Fn glob
argument
stores the number of matched pathnames into the
Fa gl_pathc
field, and a pointer to a list of pointers to pathnames into the
Fa 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
Fa pglob .
The
Fn glob
function allocates other space as needed, including the memory pointed
to by
Fa gl_pathv .
The argument
Fa flags
is used to modify the behavior of
Fn glob .
The value of
Fa flags
is the bitwise inclusive
OR
of any of the following
values defined in
glob.h
- GLOB_APPEND
-
Append pathnames generated to the ones from a previous call (or calls)
to
Fn glob .
The value of
Fa 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
Fa gl_offs
when
GLOB_DOOFFS
is set, nor (obviously) call
Fn globfree
for
Fa pglob .
- GLOB_DOOFFS
-
Make use of the
Fa gl_offs
field.
If this flag is set,
Fa gl_offs
is used to specify how many
NULL
pointers to prepend to the beginning
of the
Fa gl_pathv
field.
In other words,
Fa gl_pathv
will point to
Fa gl_offs
NULL
pointers,
followed by
Fa gl_pathc
pathname pointers, followed by a
NULL
pointer.
- GLOB_ERR
-
Causes
Fn glob
to return when it encounters a directory that it cannot open or read.
Ordinarily,
Fn glob
continues to find matches.
- GLOB_MARK
-
Each pathname that is a directory that matches
Fa pattern
has a slash
appended.
- GLOB_NOCHECK
-
If
Fa pattern
does not match any pathname, then
Fn glob
returns a list
consisting of only
Fa pattern ,
with the number of total pathnames is set to 1, and the number of matched
pathnames set to 0.
If
GLOB_QUOTE
is set, its effect is present in the pattern returned.
- GLOB_NOSORT
-
By default, the pathnames are sorted in ascending
ASCII
order;
this flag prevents that sorting (speeding up
Fn glob ) .
The following values may also be included in
Fa flags ,
however, they are non-standard extensions to
St -p1003.2 .
- GLOB_ALTDIRFUNC
-
The following additional fields in the pglob structure have been
initialized with alternate functions for glob to use to open, read,
and close directories and to get stat information on names found
in those directories.
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
-
Pre-process the pattern string to expand
`{pat,pat,...}'
strings like
csh(1).Thepattern
`{}'
is left unexpanded for historical reasons
(Csh1
does the same thing to
ease typing
of
find(1)
patterns).
- GLOB_MAGCHAR
-
Set by the
Fn glob
function if the pattern included globbing characters.
See the description of the usage of the
Fa gl_matchc
structure member for more details.
- GLOB_NOMAGIC
-
Is the same as
GLOB_NOCHECK
but it only appends the
Fa 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_QUOTE
-
Use the backslash
(`\'
)
character for quoting: every occurrence of
a backslash followed by a character in the pattern is replaced by that
character, avoiding any special interpretation of the character.
- GLOB_TILDE
-
Expand patterns that start with
`~'
to user name home directories.
If, during the search, a directory is encountered that cannot be opened
or read and
Fa errfunc
is
non- NULL ,
Fn glob
calls
Fa (*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
Fa 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
Fa errfunc
returns non-zero,
Fn glob
stops the scan and returns
GLOB_ABEND
after setting
Fa gl_pathc
and
Fa gl_pathv
to reflect any paths already matched.
This also happens if an error is encountered and
GLOB_ERR
is set in
Fa flags ,
regardless of the return value of
Fa errfunc ,
if called.
If
GLOB_ERR
is not set and either
Fa errfunc
is
NULL
or
Fa errfunc
returns zero, the error is ignored.
The
Fn globfree
function frees any space associated with
Fa pglob
from a previous call(s) to
Fn glob .
RETURN VALUES
On successful completion,
Fn glob
returns zero.
In addition the fields of
Fa pglob
contain the values described below:
- Fa gl_pathc
-
contains the total number of matched pathnames so far.
This includes other matches from previous invocations of
Fn glob
if
GLOB_APPEND
was specified.
- Fa gl_matchc
-
contains the number of matched pathnames in the current invocation of
Fn glob .
- Fa gl_flags
-
contains a copy of the
Fa flags
parameter with the bit
GLOB_MAGCHAR
set if
Fa pattern
contained any of the special characters ``*'', ``?'' or ``['', cleared
if not.
- Fa gl_pathv
-
contains a pointer to a
NULL -terminated
list of matched pathnames.
However, if
Fa gl_pathc
is zero, the contents of
Fa gl_pathv
are undefined.
If
Fn 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
Aq Pa glob.h :
- GLOB_NOSPACE
-
An attempt to allocate memory failed.
- GLOB_ABEND
-
The scan was stopped because an error was encountered and either
GLOB_ERR
was set or
Fa (*errfunc)()
returned non-zero.
The arguments
Fa pglob->gl_pathc
and
Fa pglob->gl_pathv
are still set as specified above.
EXAMPLE
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);
SEE ALSO
sh(1),
fnmatch(3),
regexp(3)
STANDARDS
The
Fn glob
function is expected to be
St -p1003.2
compatible with the exception
that the flags
GLOB_ALTDIRFUNC,
GLOB_BRACE
GLOB_MAGCHAR,
GLOB_NOMAGIC,
GLOB_QUOTE,
and
GLOB_TILDE,
and the fields
Fa gl_matchc
and
Fa gl_flags
should not be used by applications striving for strict
POSIX
conformance.
HISTORY
The
Fn glob
and
Fn globfree
functions first appeared in
BSD 4.4
BUGS
Patterns longer than
MAXPATHLEN
may cause unchecked errors.
The
Fn 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).
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUES
-
- EXAMPLE
-
- SEE ALSO
-
- STANDARDS
-
- HISTORY
-
- BUGS
-
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Time: 19:41:59 GMT, December 25, 2022