GLOB(3) BSD Library Functions Manual GLOB(3)
NAME
glob, globfree -- generate pathnames matching a pattern
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
##include <>
int
glob(const char *pattern, int flags, int (*errfunc)(const char *, int),
globt *pglob);
void
globfree(globt *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 defines the structure type globt, which con-
tains at least the following fields:
typedef struct {
int glpathc; /* count of total paths so far */
int glmatchc; /* count of paths matching pattern */
int gloffs; /* reserved at beginning of glpathv */
int glflags; /* returned flags */
char **glpathv; /* list of paths matching pattern */
} globt;
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 file-
name component of pattern that contains any of the special characters
`*', `?' or `['.
The glob() argument stores the number of matched pathnames into the
glpathc field, and a pointer to a list of pointers to pathnames into the
glpathv field. The first pointer after the last pathname is NUL. 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 glpathv.
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 :
GLOBAPEND Append pathnames generated to the ones from a previous
call (or calls) to glob(). The value of glpathc 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
GLOBDOFS flag, nor change the value of gloffs when
GLOBDOFS is set, nor (obviously) call globfree() for
pglob.
GLOBDOFS Make use of the gloffs field. If this flag is set,
gloffs is used to specify how many NUL pointers to
prepend to the beginning of the glpathv field. In
other words, glpathv will point to gloffs NUL point-
ers, followed by glpathc pathname pointers, followed by
a NUL pointer.
GLOBER Causes glob() to return when it encounters a directory
that it cannot open or read. Ordinarily, glob() contin-
ues to find matches.
GLOBMARK Each pathname that is a directory that matches pattern
has a slash appended.
GLOBNOCHECK If pattern does not match any pathname, then glob()
returns a list consisting of only pattern, with the num-
ber 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.
GLOBNOESCAPE By default, a backslash (`\') character is used to
escape the following character in the pattern, avoiding
any special interpretation of the character. If
GLOBNOESCAPE is set, backslash escaping is disabled.
GLOBNOSORT By default, the pathnames are sorted in ascending ASCI
order; this flag prevents that sorting (speeding up
glob()).
The following values may also be included in flags, however, they are
non-standard extensions to IE Std 1003.2 (``POSIX.2'').
GLOBALTDIRFUNC 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 *(*glopendir)(const char * name);
struct dirent *(*glreaddir)(void *);
void (*glclosedir)(void *);
int (*gllstat)(const char *name, struct stat *st);
int (*glstat)(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.
GLOBRACE Pre-process the pattern string to expand `{pat,pat,...}'
strings like csh(1). The pattern `{}' is left unex-
panded for historical reasons (and csh(1) does the same
thing to ease typing of find(1) patterns).
GLOBMAGCHAR Set by the glob() function if the pattern included glob-
bing characters. See the description of the usage of
the glmatchc structure member for more details.
GLOBNOMAGIC Is the same as GLOBNOCHECK but it only appends the
pattern if it does not contain any of the special char-
acters ``*'', ``?'' or ``[''. GLOBNOMAGIC is provided
to simplify implementing the historic csh(1) globbing
behavior and should probably not be used anywhere else.
GLOBTILDE Expand patterns that start with `~' to user name home
directories.
GLOBLIMIT Limit the total number of returned pathnames to the
value provided in glmatchc (default ARGMAX). 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-NUL, 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 GLOBER flag will still cause an imme-
diate return when this happens.
If errfunc returns non-zero, glob() stops the scan and returns
GLOBABORTED after setting glpathc and glpathv to reflect any paths
already matched. This also happens if an error is encountered and
GLOBER is set in flags, regardless of the return value of errfunc, if
called. If GLOBER is not set and either errfunc is NUL or errfunc
returns zero, the error is ignored.
The globfree() function frees any space associated with pglob from a pre-
vious call(s) to glob().
RETURN VALUES
On successful completion, glob() returns zero. In addition the fields of
pglob contain the values described below:
glpathc contains the total number of matched pathnames so far.
This includes other matches from previous invocations of
glob() if GLOBAPEND was specified.
glmatchc contains the number of matched pathnames in the current
invocation of glob().
glflags contains a copy of the flags argument with the bit
GLOBMAGCHAR set if pattern contained any of the special
characters ``*'', ``?'' or ``['', cleared if not.
glpathv contains a pointer to a NUL-terminated list of matched
pathnames. However, if glpathc is zero, the contents of
glpathv 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
:
GLOBNOSPACE An attempt to allocate memory failed, or if errno was 0
GLOBLIMIT was specified in the flags and pglob->glmatchc
or more patterns were matched.
GLOBABORTED The scan was stopped because an error was encountered and
either GLOBER was set or (*errfunc)() returned non-zero.
GLOBNOMATCH The pattern did not match a pathname and GLOBNOCHECK was
not set.
The arguments pglob->glpathc and pglob->glpathv are still set as speci-
fied above.
EXAMPLES
A rough equivalent of `ls -l *.c *.h' can be obtained with the following
code:
globt g;
g.gloffs = 2;
glob("*.c", GLOBDOFS, NUL, &g);
glob("*.h", GLOBDOFS GLOBAPEND, NUL, &g);
g.glpathv[0] = "ls";
g.glpathv[1] = "-l";
execvp("ls", g.glpathv);
SEE ALSO
sh(1), fnmatch(3), regexp(3)
STANDARDS
The current implementation of the glob() function does not conform to
IE Std 1003.2 (``POSIX.2''). Collating symbol expressions, equivalence
class expressions and character class expressions are not supported.
The flags GLOBALTDIRFUNC, GLOBRACE, GLOBLIMIT, GLOBMAGCHAR,
GLOBNOMAGIC, and GLOBTILDE, and the fields glmatchc and glflags 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 4.4BSD.
BUGS
Patterns longer than MAXPATHLEN may cause unchecked errors.
The glob() argument may fail and set errno for any of the errors speci-
fied for the library routines stat(2), closedir(3), opendir(3),
readdir(3), malloc(3), and free(3).
BSD September 1, 2004 BSD
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