New quoted string handling and simple pattern matching.

[mLib] / str.c

/* -*-c-*-
 *
 * $Id: str.c,v 1.4 2000/10/08 09:43:34 mdw Exp $
 *
 * Functions for hacking with strings
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * mLib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: str.c,v $
 * Revision 1.4  2000/10/08 09:43:34  mdw
 * New quoted string handling and simple pattern matching.
 *
 * Revision 1.3  1999/12/22 15:41:14  mdw
 * Skip past trailing whitespace in str_getword.
 *
 * Revision 1.2  1999/05/26 20:52:57  mdw
 * Add new `rest' argument for `str_split'.
 *
 * Revision 1.1  1999/05/17 20:37:01  mdw
 * Some trivial string hacks.
 *
 */

/*----- Header files ------------------------------------------------------*/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "str.h"

/*----- Main code ---------------------------------------------------------*/

/* --- @str_qword@ --- *
 *
 * Arguments:	@char **pp@ = address of pointer into string
 *		@unsigned f@ = various flags
 *
 * Returns:	Pointer to the next space-separated possibly-quoted word from
 *		the string, or null.
 *
 * Use:		Fetches the next word from a string.  If the flag
 *		@STRF_QUOTE@ is set, the `\' character acts as an escape, and
 *		single and double quotes protect whitespace.
 */

#define STRF_QUOTE 1u

char *str_qword(char **pp, unsigned f)
{
  char *p = *pp, *q, *qq;
  int st = 0, pst = 0;

  /* --- Preliminaries --- */

  if (!p)
    return (0);
  while (isspace((unsigned char)*p))
    p++;
  if (!*p) {
    *pp = 0;
    return (0);
  }

  /* --- Main work --- */

  for (q = qq = p; *q; q++) {
    switch (st) {
      case '\\':
	*qq++ = *q;
	st = pst;
	break;
      case '\'':
      case '\"':
	if (*q == st)
	  st = pst = 0;
	else if (*q == '\\')
	  st = '\\';
	else
	  *qq++ = *q;
	break;
      default:
	if (isspace((unsigned char)*q)) {
	  do q++; while (*q && isspace((unsigned char)*q));
	  goto done;
	} else if (!(f & STRF_QUOTE))
	  goto stdchar;
	switch (*q) {
	  case '\\':
	    st = '\\';
	    break;
	  case '\'':
	  case '\"':
	    st = pst = *q;
	    break;
	  default:
	  stdchar:
	    *qq++ = *q;
	    break;
	}
    }
  }

  /* --- Finished --- */

done:
  *pp = *q ? q : 0;
  *qq++ = 0;
  return (p);
}

/* --- @str_qsplit@ --- *
 *
 * Arguments:	@char *p@ = pointer to string
 *		@char *v[]@ = pointer to array to fill in
 *		@size_t c@ = count of strings to fill in
 *		@char **rest@ = where to store the remainder of the string
 *		@unsigned f@ = flags for @str_qword@
 *
 * Returns:	Number of strings filled in.
 *
 * Use:		Fills an array with pointers to the individual words of a
 *		string.  The string is modified in place to contain zero
 *		bytes at the word boundaries, and the words have leading
 *		and trailing space stripped off.  No more than @c@ words
 *		are read; the actual number is returned as the value of the
 *		function.  Unused slots in the array are populated with
 *		null bytes.  If there's any string left, the address of the
 *		remainder is stored in @rest@ (if it's non-null); otherwise
 *		@rest@ is set to a null pointer.
 */

size_t str_qsplit(char *p, char *v[], size_t c, char **rest, unsigned f)
{
  size_t n = 0;
  char *q;

  while (c && (q = str_qword(&p, f)) != 0) {
    *v++ = q;
    c--;
    n++;
  }
  while (c) {
    *v++ = 0;
    c--;
  }
  if (rest)
    *rest = p;
  return (n);
}

/* --- @str_getword@ --- *
 *
 * Arguments:	@char **pp@ = address of pointer into string
 *
 * Returns:	Pointer to the next space-separated word from the string,
 *		or null.
 *
 * Use:		Parses off space-separated words from a string.  This is a
 *		compatibility veneer over @str_qword@.
 */

char *str_getword(char **pp)
{
  return (str_qword(pp, 0));
}

/* --- @str_split@ --- *
 *
 * Arguments:	@char *p@ = pointer to string
 *		@char *v[]@ = pointer to array to fill in
 *		@size_t c@ = count of strings to fill in
 *		@char **rest@ = where to store the remainder of the string
 *
 * Returns:	Number of strings filled in.
 *
 * Use:		Fills an array with pointers to the individual words of a
 *		string.  This is a compatibility veneer over @str_qsplit@.
 */

size_t str_split(char *p, char *v[], size_t c, char **rest)
{
  return (str_qsplit(p, v, c, rest, 0));
}

/* --- @str_match@ --- *
 *
 * Arguments:	@const char *p@ = pointer to pattern string
 *		@const char *s@ = string to compare with
 *
 * Returns:	Nonzero if the pattern matches the string.
 *
 * Use:		Does simple wildcard matching.  This is quite nasty and more
 *		than a little slow.  Supports metacharacters `*', `?' and
 *		'['.
 */

int str_match(const char *p, const char *s)
{
  for (;;) {
    char pch = *p++, pche, sch;
    int sense;

    switch (pch) {
      case '?':
	if (!*s)
	  return (0);
	s++;
	break;
      case '*':
	if (!*p)
	  return (1);
	while (*s) {
	  if (str_match(p, s))
	    return (1);
	  s++;
	}
	return (0);
      case '[':
	if (!*s)
	  return (0);
	sch = *s++;
	pch = *p++;
	sense = 1;
	if (pch == '^' || pch == '!') {
	  sense = !sense;
	  pch = *p++;
	}
	if (pch == ']') {
	  if (*p == '-' && p[1] && p[1] != ']') {
	    pche = p[1];
	    p += 2;
	    if (pch <= sch && sch <= pche)
	      goto class_match;
	  } else if (pch == sch)
	    goto class_match;
	  pch = *p++;
	}
	for (;; pch = *p++) {
	  if (!pch || pch == ']')
	    goto class_nomatch;
	  if (*p == '-' && p[1] && p[1] != ']') {
	    pche = p[1];
	    p += 2;
	    if (pch <= sch && sch <= pche)
	      goto class_match;
	  } else if (pch == sch)
	    goto class_match;
	}
      class_match:
	if (!sense)
	  return (0);
	for (;;) {
	  pch = *p++;
	  if (!pch)
	    return (0);
	  if (pch == ']')
	    break;
	  if (*p == '-' && p[1] && p[1] != ']')
	    p += 2;
	}
	break;
      class_nomatch:
	if (sense)
	  return (0);
	break;
      case '\\':
	pch = *p++;
      default:
	if (pch != *s)
	  return (0);
	if (!pch)
	  return (1);
	s++;
	break;
    }
  }
}

/* --- @str_sanitize@ --- *
 *
 * Arguments:	@char *d@ = destination buffer
 *		@const char *p@ = pointer to source string
 *		@size_t sz@ = size of destination buffer
 *
 * Returns:	---
 *
 * Use:		Writes a string into a buffer, being careful not to overflow
 *		the buffer, to null terminate the result, and to prevent
 *		nasty nonprintable characters ending up in the buffer.
 */

void str_sanitize(char *d, const char *p, size_t sz)
{
  if (!sz)
    return;
  sz--;
  while (*p && sz) {
    int ch = *p++;
    if (!isgraph((unsigned char)ch))
      ch = '_';
    *d++ = ch;
    sz--;
  }
  *d++ = 0;
}

/*----- That's all, folks -------------------------------------------------*/