FNMATCH(3C) Standard C Library Functions FNMATCH(3C)

NAME

fnmatch - match filename or path name

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <fnmatch.h>

int
fnmatch(const char *pattern, const char *string, int flags);

DESCRIPTION

The fnmatch() function matches patterns as described on the fnmatch(7)
manual page (with the exceptions noted in the STANDARDS). It checks
the string argument to see if it matches the pattern argument.

The flags argument modifies the interpretation of pattern and string.
It is the bitwise inclusive OR of zero or more of the following flags
defined in the header <fnmatch.h>.

FNM_PATHNAME If set, a slash ("/") character in string will be
explicitly matched by a slash in pattern; it will not
be matched by either the asterisk ("*") or question-
mark ("?") special characters, nor by a bracket ("[]")
expression.

If not set, the slash character is treated as an
ordinary character.

FNM_IGNORECASE If set, the string will be transliterated to lower
case before doing the actual match. This
transliteration is done using towlower_l(3C), using
the locale of the current thread. If no locale is
set, then the global locale is used instead.

If not set, the match will use string with no changes,
making the match case-sensitive.

For compatibility with FreeBSD implementation of
fnmatch(), header <fnmatch.h> provides the
FNM_CASEFOLD flag having the same meaning.

FNM_NOESCAPE If not set, a backslash character ("\") in pattern
followed by any other character will match that second
character in string. In particular, "\\" will match a
backslash in string.

If set, a backslash character will be treated as an
ordinary character.

FNM_PERIOD If set, a leading period in string will match a period
in pattern; where the location of "leading" is
indicated by the value of FNM_PATHNAME:

+o If FNM_PATHNAME is set, a period is "leading" if
it is the first character in string or if it
immediately follows a slash.

+o If FNM_PATHNAME is not set, a period is "leading"
only if it is the first character of string.

If not set, no special restrictions are placed on
matching a period.

FNM_LEADING_DIR Match if pattern matches initial segment of string
which is followed by a slash.

RETURN VALUES

If string matches the pattern specified by pattern, then fnmatch()
returns 0. If there is no match, fnmatch() returns FNM_NOMATCH, which
is defined in the header <fnmatch.h>. If an error occurs, fnmatch()
returns another non-zero value.

USAGE

The fnmatch() function has two major uses. It could be used by an
application or utility that needs to read a directory and apply a
pattern against each entry. The find(1) utility is an example of this.
It can also be used by the pax(1) utility to process its pattern
operands, or by applications that need to match strings in a similar
manner.

The name fnmatch() is intended to imply filename match, rather than
pathname match. The default action of this function is to match
filenames, rather than path names, since it gives no special
significance to the slash character. With the FNM_PATHNAME flag,
fnmatch() does match path names, but without tilde expansion, parameter
expansion, or special treatment for period at the beginning of a
filename.

CODE SET INDEPENDENCE

Enabled

INTERFACE STABILITY

Standard

MT-LEVEL
MT-Safe with exceptions

The fnmatch() function can be used safely in multithreaded
applications, as long as setlocale(3C) is not being called to change
the locale.

SEE ALSO

find(1), pax(1), glob(3C), setlocale(3C), wordexp(3C), attributes(7),
fnmatch(7), standards(7)

STANDARDS

The current implementation of the fnmatch() function does not conform
to IEEE Std 1003.2 ("POSIX.2"). Collating symbol expressions,
equivalence class expressions and character class expressions are not
supported.

BUGS

The pattern "*" matches the empty string, even if FNM_PATHNAME is
specified.

illumos July 12, 2024 illumos