str: Various whitespace cleanups.

[mLib] / str.c

/* -*-c-*-
 *
 * $Id: str.c,v 1.6 2004/04/08 01:36:13 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.
 */

/*----- 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.
 */

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 -------------------------------------------------*/