SYNOPSIS

#include <regexp.h>
string regreplace( string txt, string pattern, closure|string replacepattern, int flags)

DESCRIPTION

This function looks through txt looking for the regular expression pattern. If it finds it, it replaces it by the replacepattern.

The replacepattern can be a constant string, or a closure taking the matched substring and the position at which it was found as arguments and returning the replacement pattern string.

The flag is a bitmask of the usual regexp options. Additionally the efun recognizes RE_GLOBAL: if set, the search and replace is repeated as often as the pattern matches.

The function returns the modified string (or the original if it wasn’t modified).

The function behaves like the s/pattern/replacepattern/flags in editors as ed/vi or sed. The power of this function lies in replacing variable strings (as opposed to regexplode, where you can explode by regular expression, but not implode...)

USAGE

string msgin;

// Checks msgin for the string 'tells you: ' and all following
// characters and encloses those characters by <underline>
// and </underline>. global.
//
msgin = regreplace(msgin, "tells you: (.*)",
         "tells you: <underline>\\1</underline>", 1);

// replaces all <underline> html tags by the vt100 escape
// sequence for underline.
//
txt = regreplace(txt, "<underline>", "<ESC>[5m", 1);

// Put the word HOUSE into lower case.
txt = regreplace(txt, "HOUSE",
        function string (string s) {return lower_case(s);},
        1);

HISTORY

  • introduced (3.2.1@125)
  • changed (3.2.9) – accepts a closure as replacepattern

LORE

Author
Marcus@TAPPMud contributed the original idea for the efun and the man page.