fnmatch - match a filename or a pathname
#include <fnmatch.h> int fnmatch(const char *pattern, const char *string, int flags);
The fnmatch() function matches patterns as described in the XCU specification, Section 2.13.1, Patterns Matching a Single Character, and Section 2.13.2, Patterns Matching Multiple Characters. It checks the string specified by the string argument to see if it matches the pattern specified by 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 flags defined in the header <fnmatch.h>. If the FNM_PATHNAME flag is set in flags, then 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 the FNM_PATHNAME flag is not set, the slash character is treated as an ordinary character.
If FNM_NOESCAPE is not set in flags, 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 FNM_NOESCAPE is set, a backslash character will be treated as an ordinary character.
If FNM_PERIOD is set in flags, then a leading period in string will match a period in pattern; as described by rule 2 in the XCU specification, Section 2.13.3, Patterns Used for Filename Expansion where the location of "leading" is indicated by the value of FNM_PATHNAME:
- If FNM_PATHNAME is set, a period is "leading" if it is the first character in string or if it immediately follows a slash.
- If FNM_PATHNAME is not set, a period is "leading" only if it is the first character of string.
If FNM_PERIOD is not set, then no special restrictions are placed on matching a period.
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.
No errors are defined.
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 utility is an example of this. It can also be used by the pax 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 pathnames, since it gives no special significance to the slash character. With the FNM_PATHNAME flag, fnmatch() does match pathnames, but without tilde expansion, parameter expansion, or special treatment for period at the beginning of a filename.
glob(), wordexp(), <fnmatch.h>, the XCU specification.
Derived from the ISO POSIX-2 standard.