diff options
Diffstat (limited to 'lib/libutil/fparseln.c')
| -rw-r--r-- | lib/libutil/fparseln.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/lib/libutil/fparseln.c b/lib/libutil/fparseln.c new file mode 100644 index 000000000000..ba7c4b45f291 --- /dev/null +++ b/lib/libutil/fparseln.c @@ -0,0 +1,233 @@ +/* $NetBSD: fparseln.c,v 1.9 1999/09/20 04:48:06 lukem Exp $ */ + +/* + * Copyright (c) 1997 Christos Zoulas. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Christos Zoulas. + * 4. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <assert.h> +#include <errno.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <libutil.h> + +static int isescaped __P((const char *, const char *, int)); + +/* isescaped(): + * Return true if the character in *p that belongs to a string + * that starts in *sp, is escaped by the escape character esc. + */ +static int +isescaped(sp, p, esc) + const char *sp, *p; + int esc; +{ + const char *cp; + size_t ne; + +#if 0 + _DIAGASSERT(sp != NULL); + _DIAGASSERT(p != NULL); +#endif + + /* No escape character */ + if (esc == '\0') + return 1; + + /* Count the number of escape characters that precede ours */ + for (ne = 0, cp = p; --cp >= sp && *cp == esc; ne++) + continue; + + /* Return true if odd number of escape characters */ + return (ne & 1) != 0; +} + + +/* fparseln(): + * Read a line from a file parsing continuations ending in \ + * and eliminating trailing newlines, or comments starting with + * the comment char. + */ +char * +fparseln(fp, size, lineno, str, flags) + FILE *fp; + size_t *size; + size_t *lineno; + const char str[3]; + int flags; +{ + static const char dstr[3] = { '\\', '\\', '#' }; + + size_t s, len; + char *buf; + char *ptr, *cp; + int cnt; + char esc, con, nl, com; + +#if 0 + _DIAGASSERT(fp != NULL); +#endif + + len = 0; + buf = NULL; + cnt = 1; + + if (str == NULL) + str = dstr; + + esc = str[0]; + con = str[1]; + com = str[2]; + /* + * XXX: it would be cool to be able to specify the newline character, + * but unfortunately, fgetln does not let us + */ + nl = '\n'; + + while (cnt) { + cnt = 0; + + if (lineno) + (*lineno)++; + + if ((ptr = fgetln(fp, &s)) == NULL) + break; + + if (s && com) { /* Check and eliminate comments */ + for (cp = ptr; cp < ptr + s; cp++) + if (*cp == com && !isescaped(ptr, cp, esc)) { + s = cp - ptr; + cnt = s == 0 && buf == NULL; + break; + } + } + + if (s && nl) { /* Check and eliminate newlines */ + cp = &ptr[s - 1]; + + if (*cp == nl) + s--; /* forget newline */ + } + + if (s && con) { /* Check and eliminate continuations */ + cp = &ptr[s - 1]; + + if (*cp == con && !isescaped(ptr, cp, esc)) { + s--; /* forget escape */ + cnt = 1; + } + } + + if (s == 0 && buf != NULL) + continue; + + if ((cp = realloc(buf, len + s + 1)) == NULL) { + free(buf); + return NULL; + } + buf = cp; + + (void) memcpy(buf + len, ptr, s); + len += s; + buf[len] = '\0'; + } + + if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL && + strchr(buf, esc) != NULL) { + ptr = cp = buf; + while (cp[0] != '\0') { + int skipesc; + + while (cp[0] != '\0' && cp[0] != esc) + *ptr++ = *cp++; + if (cp[0] == '\0' || cp[1] == '\0') + break; + + skipesc = 0; + if (cp[1] == com) + skipesc += (flags & FPARSELN_UNESCCOMM); + if (cp[1] == con) + skipesc += (flags & FPARSELN_UNESCCONT); + if (cp[1] == esc) + skipesc += (flags & FPARSELN_UNESCESC); + if (cp[1] != com && cp[1] != con && cp[1] != esc) + skipesc = (flags & FPARSELN_UNESCREST); + + if (skipesc) + cp++; + else + *ptr++ = *cp++; + *ptr++ = *cp++; + } + *ptr = '\0'; + len = strlen(buf); + } + + if (size) + *size = len; + return buf; +} + +#ifdef TEST + +int main __P((int, char **)); + +int +main(argc, argv) + int argc; + char **argv; +{ + char *ptr; + size_t size, line; + + line = 0; + while ((ptr = fparseln(stdin, &size, &line, NULL, + FPARSELN_UNESCALL)) != NULL) + printf("line %d (%d) |%s|\n", line, size, ptr); + return 0; +} + +/* + +# This is a test +line 1 +line 2 \ +line 3 # Comment +line 4 \# Not comment \\\\ + +# And a comment \ +line 5 \\\ +line 6 + +*/ + +#endif /* TEST */ |