glob (7) ( Русские man: Макропакеты и соглашения )
BSD mandoc
NAME
globglobfree
- generate pathnames matching a pattern
LIBRARY
Lb libc
SYNOPSIS
#include <glob.h> int
glob (const char *pattern int flags int (*errfunc)(const char *, int) glob_t *pglob); void
globfree (glob_t *pglob);
DESCRIPTION
The
glob ();
function
is a pathname generator that implements the rules for file name pattern
matching used by the shell.
The include file
#include <glob.h>
defines the structure type
Fa 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
Fa 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
Fa pattern
that contains any of the special characters
`*'
,
`?'
or
`['
The
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
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
glob (.);
The value of
Fa flags
is the bitwise inclusive
OR
of any of the following
values defined in
In glob.h :
GLOB_APPEND
Append pathnames generated to the ones from a previous call (or calls)
to
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
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
glob ();
to return when it encounters a directory that it cannot open or read.
Ordinarily,
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
glob ();
returns a list
consisting of only
Fa 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
By default, a backslash
(`\'
)
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
By default, the pathnames are sorted in ascending
ASCII
order;
this flag prevents that sorting (speeding up
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).
The pattern
`{}'
is left unexpanded for historical reasons (and
csh(1)
does the same thing to
ease typing
of
find(1)
patterns).
GLOB_MAGCHAR
Set by the
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_TILDE
Expand patterns that start with
`~'
to user name home directories.
GLOB_LIMIT
Limit the total number of returned pathnames to the value provided in
Fa gl_matchc
(default
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
Fa errfunc
is
non- NULL
glob ();
calls
Fa *errfunc Ns ( Fa 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
Er ENOENT
and
Er ENOTDIR ;
however, the
GLOB_ERR
flag will still cause an immediate
return when this happens.
If
Fa errfunc
returns non-zero,
glob ();
stops the scan and returns
GLOB_ABORTED
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
globfree ();
function frees any space associated with
Fa pglob
from a previous call(s) to
glob (.);
RETURN VALUES
On successful completion,
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
glob ();
if
GLOB_APPEND
was specified.
Fa gl_matchc
contains the number of matched pathnames in the current invocation of
glob (.);
Fa gl_flags
contains a copy of the
Fa flags
argument 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
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
In glob.h :
GLOB_NOSPACE
An attempt to allocate memory failed, or if
Fa errno
was 0
GLOB_LIMIT
was specified in the flags and
Fa pglob->gl_matchc
or more patterns were matched.
GLOB_ABORTED
The scan was stopped because an error was encountered and either
GLOB_ERR
was set or
Fa *errfunc
returned non-zero.
GLOB_NOMATCH
The pattern did not match a pathname and
GLOB_NOCHECK
was not set.
The arguments
Fa pglob->gl_pathc
and
Fa pglob->gl_pathv
are still set as specified above.
EXAMPLES
A rough equivalent of
`ls'
-l *.c *.h
can be obtained with the
following code:
The current implementation of the
glob ();
function
does not
conform to
St -p1003.2 .
Collating symbol expressions, equivalence class expressions and
character class expressions are not supported.
The flags
GLOB_ALTDIRFUNCGLOB_BRACEGLOB_LIMITGLOB_MAGCHARGLOB_NOMAGIC
and
GLOB_TILDE
and the fields
Fa gl_matchc
and
Fa gl_flags
are extensions to the
POSIX
standard and
should not be used by applications striving for strict
conformance.
HISTORY
The
glob ();
and
globfree ();
functions first appeared in
BSD 4.4
BUGS
Patterns longer than
MAXPATHLEN
may cause unchecked errors.
The
glob ();
argument
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).
