/* $NetBSD: fparseln.c,v 1.1.1.1 2020/06/15 01:52:54 christos 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. * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #if defined(LIBC_SCCS) && !defined(lint) __RCSID("$NetBSD: fparseln.c,v 1.1.1.1 2020/06/15 01:52:54 christos Exp $"); #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #if ! HAVE_FPARSELN || BROKEN_FPARSELN #define FLOCKFILE(fp) #define FUNLOCKFILE(fp) #if defined(_REENTRANT) && !HAVE_NBTOOL_CONFIG_H #define __fgetln(f, l) __fgetstr(f, l, '\n') #else #define __fgetln(f, l) fgetln(f, l) #endif static int isescaped(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(const char *sp, const char *p, int esc) { const char *cp; size_t ne; /* No escape character */ if (esc == '\0') return 0; /* 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(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; 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'; FLOCKFILE(fp); 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 continuation char */ cnt = 1; } } if (s == 0) { /* * nothing to add, skip realloc except in case * we need a minimal buf to return an empty line */ if (cnt || buf != NULL) continue; } if ((cp = realloc(buf, len + s + 1)) == NULL) { FUNLOCKFILE(fp); free(buf); return NULL; } buf = cp; (void) memcpy(buf + len, ptr, s); len += s; buf[len] = '\0'; } FUNLOCKFILE(fp); 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(int, char **); int main(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 */ #endif /* ! HAVE_FPARSELN || BROKEN_FPARSELN */