unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (SunOS-5.9)
Page:
Section:
Apropos / Subsearch:
optional field



Standards, Environments, and Macros                    fnmatch(5)



NAME
     fnmatch - file name pattern matching

DESCRIPTION
     The pattern matching notation described below   is  used  to
     specify patterns for matching strings in the shell. Histori-
     cally, pattern matching notation is related to, but slightly
     different  from,  the  regular expression notation. For this
     reason, the description of the rules for this pattern match-
     ing  notation is based on the description of regular expres-
     sion notation described on the  regex(5) manual page.

  Patterns Matching a Single Character
     The following patterns matching a single character  match  a
     single character: ordinary characters, special pattern char-
     acters and pattern bracket expressions. The pattern  bracket
     expression will also match a single collating element.

     An ordinary character is a pattern that matches  itself.  It
     can  be  any character in the supported character set except
     for NUL, those special shell characters that  require  quot-
     ing,  and  the  following  three special pattern characters.
     Matching is based on the bit pattern used for  encoding  the
     character,  not on the graphic representation of the charac-
     ter. If any character (ordinary, shell special,  or  pattern
     special)  is  quoted,  that pattern will match the character
     itself. The shell special characters always require quoting.

     When unquoted and outside a bracket expression, the  follow-
     ing  three  characters  will  have  special  meaning  in the
     specification of patterns:

      ?    A question-mark is a pattern that will match any char-
           acter.

     *     An asterisk is a  pattern  that  will  match  multiple
           characters, as described in Patterns Matching Multiple
           Characters, below.

     [     The open bracket  will  introduce  a  pattern  bracket
           expression.

     The description of basic regular expression bracket  expres-
     sions  on  the regex(5) manual page also applies to the pat-
     tern bracket expression, except  that  the  exclamation-mark
     character ( ! ) replaces the circumflex character (^) in its
     role in a non-matching list in the regular expression  nota-
     tion. A bracket expression starting with an unquoted circum-
     flex character produces unspecified results.

     The restriction on a circumflex in a bracket  expression  is
     to allow implementations that support pattern matching using



SunOS 5.9           Last change: 28 Mar 1995                    1






Standards, Environments, and Macros                    fnmatch(5)



     the circumflex as the negation character in addition to  the
     exclamation-mark.  A portable application must use something
     like [\^!] to match either character.

     When pattern matching is used where shell quote  removal  is
     not  performed  (such  as  in the argument to the find -name
     primary when find is being called using  one  of  the   exec
     functions,  or  in  the  pattern argument to the fnmatch(3C)
     function, special characters can be escaped to remove  their
     special  meaning  by preceding them with a backslash charac-
     ter. This escaping backslash will be discarded. The sequence
     \\ represents one literal backslash. All of the requirements
     and effects of quoting on ordinary, shell special  and  spe-
     cial  pattern characters will apply to escaping in this con-
     text.

     Both quoting and escaping are described here because pattern
     matching must work in three separate circumstances:

        o  Calling directly upon the shell, such as  in  pathname
           expansion or in a case statement. All of the following
           will match the string or file abc:


           abc          "abc"          a"b"c         a\bc          a[b]c
           a["b"]c      a[\b]c         a["\b"]c      a?c           a*c


           The following will not:


     "a?c"                a\*c                  a\[b]c


        o  Calling a utility or function without going through  a
           shell,  as  described  for  find(1)  and  the function
           fnmatch(3C)

        o  Calling utilities such  as  find,  cpio,  tar  or  pax
           through  the  shell  command line. In this case, shell
           quote removal is performed before the utility sees the
           argument.  For example, in:

           find /bin -name e\c[\h]o -print


     after quote removal, the backslashes are presented  to  find
     and  it treats them as escape characters. Both precede ordi-
     nary characters, so the c and  h  represent  themselves  and
     echo would be found on many historical systems (that have it
     in /bin). To find a file name that contained  shell  special
     characters  or pattern characters, both quoting and escaping



SunOS 5.9           Last change: 28 Mar 1995                    2






Standards, Environments, and Macros                    fnmatch(5)



     are required, such as:

           pax -r ...  "*a\(\?"



     to extract a filename ending  with  a(?.Conforming  applica-
     tions  are  required  to  quote  or escape the shell special
     characters  (sometimes  called  metacharacters).   If   used
     without  this protection, syntax errors can result or imple-
     mentation extensions can  be  triggered.  For  example,  the
     KornShell   supports   a   series  of  extensions  based  on
     parentheses in patterns; see  ksh(1)

  Patterns Matching Multiple Characters
     The following rules are used to construct patterns  matching
     multiple  characters from patterns matching a single charac-
     ter:

        o  The asterisk (*) is a  pattern  that  will  match  any
           string, including the null string.

        o  The concatenation of patterns matching a single  char-
           acter  is a valid pattern that will match the concate-
           nation of the single characters or collating  elements
           matched by each of the concatenated patterns.

        o  The concatenation of one or more patterns  matching  a
           single character with one or more asterisks is a valid
           pattern. In such patterns, each asterisk will match  a
           string  of  zero  or  more  characters,  matching  the
           greatest possible  number  of  characters  that  still
           allows  the  remainder  of  the  pattern  to match the
           string.

     Since each asterisk matches zero or  more  occurrences,  the
     patterns a*b and  a**b have identical functionality.

     Examples:

      a[bc]
           matches the strings ab and ac.

     a*d   matches the strings ad, abd  and  abcd,  but  not  the
           string abc.

     a*d*  matches the strings ad, abcd, abcdef, aaaad and adddd.

     *a*d  matches the strings ad, abcd, efabcd, aaaad and adddd.

  Patterns Used for Filename Expansion




SunOS 5.9           Last change: 28 Mar 1995                    3






Standards, Environments, and Macros                    fnmatch(5)



     The rules described so far  in  Patterns  Matching  Multiple
     Characters  and  Patterns  Matching  a  Single Character are
     qualified by the following rules  that  apply  when  pattern
     matching notation is used for filename expansion.

     1. The slash character in  a  pathname  must  be  explicitly
        matched  by using one  or more slashes in the pattern; it
        cannot be matched by the asterisk or  question-mark  spe-
        cial  characters  or by a bracket expression.  Slashes in
        the pattern are identified  before  bracket  expressions;
        thus,  a  slash  cannot  be included in a pattern bracket
        expression used for filename expansion. For example,  the
        pattern  a[b/c]d  will not match such pathnames as abd or
        a/d.  It will only match a pathname of literally a[b/c]d.

     2. If a filename begins with a period (.), the  period  must
        be  explicitly  matched  by  using  a period as the first
        character of the pattern or immediately following a slash
        character. The leading period will not be matched by:

        o the asterisk or question-mark special characters

        o a bracket expression containing  a  non-matching  list,
        such as:

        [!a]


        a range expression, such as:

        [%-0]


        or a character class expression, such as:

        [[:punct:]]


        It is unspecified whether an explicit period in a bracket
        expression matching list, such as:

        [.abc]


        can match a leading period in a filename.

     3. Specified patterns are matched against existing filenames
        and pathnames,  as appropriate.  Each component that con-
        tains a pattern character requires read permission in the
        directory   containing  that  component.  Any  component,
        except the last, that does not contain a pattern  charac-
        ter  requires  search  permission. For example, given the



SunOS 5.9           Last change: 28 Mar 1995                    4






Standards, Environments, and Macros                    fnmatch(5)



        pattern:

        /foo/bar/x*/bam


        search permission is needed for directories  /  and  foo,
        search and read permissions are needed for directory bar,
        and search permission is needed for each x* directory.

        If the pattern matches any existing  filenames  or  path-
        names,  the pattern will be replaced with those filenames
        and pathnames, sorted according to the collating sequence
        in  effect in the current locale. If the pattern contains
        an invalid bracket  expression  or  does  not  match  any
        existing  filenames  or  pathnames, the pattern string is
        left unchanged.

SEE ALSO
     find(1), ksh(1), fnmatch(3C), regex(5)




































SunOS 5.9           Last change: 28 Mar 1995                    5