fparseln.c revision 84225
1183593Sjkoshy/* $NetBSD: fparseln.c,v 1.9 1999/09/20 04:48:06 lukem Exp $ */ 2183593Sjkoshy 3183593Sjkoshy/* 4183593Sjkoshy * Copyright (c) 1997 Christos Zoulas. All rights reserved. 5183593Sjkoshy * 6183593Sjkoshy * Redistribution and use in source and binary forms, with or without 7183593Sjkoshy * modification, are permitted provided that the following conditions 8183593Sjkoshy * are met: 9183593Sjkoshy * 1. Redistributions of source code must retain the above copyright 10183593Sjkoshy * notice, this list of conditions and the following disclaimer. 11183593Sjkoshy * 2. Redistributions in binary form must reproduce the above copyright 12231871Sbrueffer * notice, this list of conditions and the following disclaimer in the 13231871Sbrueffer * documentation and/or other materials provided with the distribution. 14231871Sbrueffer * 3. All advertising materials mentioning features or use of this software 15231871Sbrueffer * must display the following acknowledgement: 16231871Sbrueffer * This product includes software developed by Christos Zoulas. 17231871Sbrueffer * 4. The name of the author may not be used to endorse or promote products 18231871Sbrueffer * derived from this software without specific prior written permission. 19231871Sbrueffer * 20231871Sbrueffer * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21231871Sbrueffer * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22231871Sbrueffer * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23183593Sjkoshy * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24183593Sjkoshy * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25183593Sjkoshy * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26184995Sjkoshy * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27206622Suqs * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28183593Sjkoshy * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29183593Sjkoshy * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30183593Sjkoshy */ 31183593Sjkoshy 32183593Sjkoshy#include <sys/cdefs.h> 33183593Sjkoshy__FBSDID("$FreeBSD: head/lib/libutil/fparseln.c 84225 2001-09-30 22:35:07Z dillon $"); 34183593Sjkoshy 35183593Sjkoshy#include <sys/types.h> 36183593Sjkoshy#include <assert.h> 37183593Sjkoshy#include <errno.h> 38183593Sjkoshy#include <stdio.h> 39183593Sjkoshy#include <string.h> 40183593Sjkoshy#include <stdlib.h> 41183593Sjkoshy#include <libutil.h> 42183593Sjkoshy 43183593Sjkoshystatic int isescaped __P((const char *, const char *, int)); 44183593Sjkoshy 45183593Sjkoshy/* isescaped(): 46183593Sjkoshy * Return true if the character in *p that belongs to a string 47183593Sjkoshy * that starts in *sp, is escaped by the escape character esc. 48183593Sjkoshy */ 49183593Sjkoshystatic int 50183593Sjkoshyisescaped(sp, p, esc) 51183593Sjkoshy const char *sp, *p; 52183593Sjkoshy int esc; 53183593Sjkoshy{ 54183593Sjkoshy const char *cp; 55183593Sjkoshy size_t ne; 56183593Sjkoshy 57183593Sjkoshy#if 0 58183593Sjkoshy _DIAGASSERT(sp != NULL); 59183593Sjkoshy _DIAGASSERT(p != NULL); 60183593Sjkoshy#endif 61183593Sjkoshy 62183593Sjkoshy /* No escape character */ 63183593Sjkoshy if (esc == '\0') 64183593Sjkoshy return 1; 65183593Sjkoshy 66183593Sjkoshy /* Count the number of escape characters that precede ours */ 67183593Sjkoshy for (ne = 0, cp = p; --cp >= sp && *cp == esc; ne++) 68183593Sjkoshy continue; 69183593Sjkoshy 70183593Sjkoshy /* Return true if odd number of escape characters */ 71183593Sjkoshy return (ne & 1) != 0; 72183593Sjkoshy} 73183593Sjkoshy 74183593Sjkoshy 75184995Sjkoshy/* fparseln(): 76196449Sjkoshy * Read a line from a file parsing continuations ending in \ 77184995Sjkoshy * and eliminating trailing newlines, or comments starting with 78183593Sjkoshy * the comment char. 79183593Sjkoshy */ 80183593Sjkoshychar * 81183593Sjkoshyfparseln(fp, size, lineno, str, flags) 82183593Sjkoshy FILE *fp; 83183593Sjkoshy size_t *size; 84183593Sjkoshy size_t *lineno; 85183593Sjkoshy const char str[3]; 86184995Sjkoshy int flags; 87184995Sjkoshy{ 88184995Sjkoshy static const char dstr[3] = { '\\', '\\', '#' }; 89184995Sjkoshy 90184995Sjkoshy size_t s, len; 91183593Sjkoshy char *buf; 92183593Sjkoshy char *ptr, *cp; 93183593Sjkoshy int cnt; 94183593Sjkoshy char esc, con, nl, com; 95183593Sjkoshy 96183593Sjkoshy#if 0 97183593Sjkoshy _DIAGASSERT(fp != NULL); 98183593Sjkoshy#endif 99183593Sjkoshy 100183593Sjkoshy len = 0; 101183593Sjkoshy buf = NULL; 102184891Sjkoshy cnt = 1; 103183593Sjkoshy 104183593Sjkoshy if (str == NULL) 105184891Sjkoshy str = dstr; 106183593Sjkoshy 107183593Sjkoshy esc = str[0]; 108184891Sjkoshy con = str[1]; 109183593Sjkoshy com = str[2]; 110183593Sjkoshy /* 111183593Sjkoshy * XXX: it would be cool to be able to specify the newline character, 112184995Sjkoshy * but unfortunately, fgetln does not let us 113184995Sjkoshy */ 114184995Sjkoshy nl = '\n'; 115184995Sjkoshy 116184995Sjkoshy while (cnt) { 117184995Sjkoshy cnt = 0; 118184995Sjkoshy 119184995Sjkoshy if (lineno) 120184995Sjkoshy (*lineno)++; 121184995Sjkoshy 122184995Sjkoshy if ((ptr = fgetln(fp, &s)) == NULL) 123184995Sjkoshy break; 124184995Sjkoshy 125183593Sjkoshy if (s && com) { /* Check and eliminate comments */ 126183593Sjkoshy for (cp = ptr; cp < ptr + s; cp++) 127183593Sjkoshy if (*cp == com && !isescaped(ptr, cp, esc)) { 128183593Sjkoshy s = cp - ptr; 129183593Sjkoshy cnt = s == 0 && buf == NULL; 130183593Sjkoshy break; 131183593Sjkoshy } 132183593Sjkoshy } 133183593Sjkoshy 134183593Sjkoshy if (s && nl) { /* Check and eliminate newlines */ 135233628Sfabient cp = &ptr[s - 1]; 136183593Sjkoshy 137183593Sjkoshy if (*cp == nl) 138183593Sjkoshy s--; /* forget newline */ 139183593Sjkoshy } 140183593Sjkoshy 141183593Sjkoshy if (s && con) { /* Check and eliminate continuations */ 142183593Sjkoshy cp = &ptr[s - 1]; 143183593Sjkoshy 144183593Sjkoshy if (*cp == con && !isescaped(ptr, cp, esc)) { 145183593Sjkoshy s--; /* forget escape */ 146183593Sjkoshy cnt = 1; 147183593Sjkoshy } 148183593Sjkoshy } 149183593Sjkoshy 150183593Sjkoshy if (s == 0 && buf != NULL) 151 continue; 152 153 if ((cp = realloc(buf, len + s + 1)) == NULL) { 154 free(buf); 155 return NULL; 156 } 157 buf = cp; 158 159 (void) memcpy(buf + len, ptr, s); 160 len += s; 161 buf[len] = '\0'; 162 } 163 164 if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL && 165 strchr(buf, esc) != NULL) { 166 ptr = cp = buf; 167 while (cp[0] != '\0') { 168 int skipesc; 169 170 while (cp[0] != '\0' && cp[0] != esc) 171 *ptr++ = *cp++; 172 if (cp[0] == '\0' || cp[1] == '\0') 173 break; 174 175 skipesc = 0; 176 if (cp[1] == com) 177 skipesc += (flags & FPARSELN_UNESCCOMM); 178 if (cp[1] == con) 179 skipesc += (flags & FPARSELN_UNESCCONT); 180 if (cp[1] == esc) 181 skipesc += (flags & FPARSELN_UNESCESC); 182 if (cp[1] != com && cp[1] != con && cp[1] != esc) 183 skipesc = (flags & FPARSELN_UNESCREST); 184 185 if (skipesc) 186 cp++; 187 else 188 *ptr++ = *cp++; 189 *ptr++ = *cp++; 190 } 191 *ptr = '\0'; 192 len = strlen(buf); 193 } 194 195 if (size) 196 *size = len; 197 return buf; 198} 199 200#ifdef TEST 201 202int main __P((int, char **)); 203 204int 205main(argc, argv) 206 int argc; 207 char **argv; 208{ 209 char *ptr; 210 size_t size, line; 211 212 line = 0; 213 while ((ptr = fparseln(stdin, &size, &line, NULL, 214 FPARSELN_UNESCALL)) != NULL) 215 printf("line %d (%d) |%s|\n", line, size, ptr); 216 return 0; 217} 218 219/* 220 221# This is a test 222line 1 223line 2 \ 224line 3 # Comment 225line 4 \# Not comment \\\\ 226 227# And a comment \ 228line 5 \\\ 229line 6 230 231*/ 232 233#endif /* TEST */ 234