regex(1F)     (Form and Menu Language Interpreter Utilities)      regex(1F)


   NAME
         regex - match patterns against a string

   SYNOPSIS
         regex [-e] [-v "string"] [pattern template] ... pattern [template]

   DESCRIPTION
         The regex command takes a string from stdin, and a list of
         pattern/template pairs, and runs regex(3X) to compare the string
         against each pattern until there is a match.  When a match occurs,
         regex writes the corresponding template to stdout and returns TRUE.
         The last (or only) pattern does not need a template.  If that is the
         pattern that matches the string, the function simply returns TRUE.
         If no match is found, regex returns FALSE.

         -e        means regex will evaluate the corresponding template and
                   write the result to stdout.

         -v "string"
                   If -v is specified, string will be used instead of stdin to
                   match against patterns.

         The argument pattern is a regular expression of the form described in
         regex(3X).  In most cases pattern should be enclosed in single quotes
         to turn off special meanings of characters.  Note that only the final
         pattern in the list may lack a template.

         The argument template may contain the strings $m0 through $m9, which
         will be expanded to the part of pattern enclosed in ( ... )$0 through
         ( ... )$9 constructs (see examples below).  Note that if you use this
         feature, you must be sure to enclose template in single quotes so
         that FMLI doesn't expand $m0 through $m9 at parse time.  This feature
         gives regex much of the power of cut(1), paste(1), and grep(1), and
         some of the capabilities of sed(1).  If there is no template, the
         default is "$m0$m1$m2$m3$m4$m5$m6$m7$m8$m9".

   EXAMPLES
         To cut the 4th through 8th letters out of a string (this example will
         output strin and return TRUE):

               `regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`

         In a form, to validate input to field 5 as an integer:

               valid=`regex -v "$F5" '^[0-9]+$'`

         In a form, to translate an environment variable which contains one of
         the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:





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   regex(1F)     (Form and Menu Language Interpreter Utilities)      regex(1F)


               value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`

         Note the use of the pattern '.*' to mean "anything else".

         In the example below, all three lines constitute a single backquoted
         expression.  This expression, by itself, could be put in a menu
         definition file.  Since backquoted expressions are expanded as they
         are parsed, and output from a backquoted expression (the cat command,
         in this example) becomes part of the definition file being parsed,
         this expression would read /etc/passwd and make a dynamic menu of all
         the login ids on the system.

               `cat /etc/passwd | regex '^([^:]*)$0.*$' '
               name=$m0
               action=`message "$m0 is a user"`'`

   DIAGNOSTICS
         If none of the patterns match, regex returns FALSE, otherwise TRUE.

   NOTES
         Patterns and templates must often be enclosed in single quotes to
         turn off the special meanings of characters.  Especially if you use
         the $m0 through $m9 variables in the template, since FMLI will expand
         the variables (usually to "") before regex even sees them.

         Single characters in character classes (inside []) must be listed
         before character ranges, otherwise they will not be recognized.  For
         example, [a-zA-Z_/] will not find underscores (_) or slashes (/), but
         [_/a-zA-Z] will.

         The regular expressions accepted by regcmp differ slightly from other
         utilities (i.e., sed, grep, awk, ed, etc.).

         regex with the -e option forces subsequent commands to be ignored.
         In other words if a backquoted statement appears as follows:

               `regex -e ...; command1; command2`

         command1 and command2 would never be executed.  However, dividing the
         expression into two:

               `regex -e ...``command1; command2`

         would yield the desired result.

   SEE ALSO
         regcmp(3), regex(3X) in the Programmer's Reference Manual.
         awk(1), cut(1), grep(1), paste(1), sed(1) in the User's Reference
         Manual.




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