From 7bcd96904137f447a8d58a8295ea58f26711ab71 Mon Sep 17 00:00:00 2001 From: Joerg Wunsch Date: Mon, 9 Dec 1996 14:05:35 +0000 Subject: pw(8) -- a backend utility to manage the user and group databases. sysinstall's new User&group menu will use it, hence it's a 2.2 candidate despite of providing new functionality. Submitted by: David L. Nugent, --- pw/fileupd.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 pw/fileupd.c (limited to 'pw/fileupd.c') diff --git a/pw/fileupd.c b/pw/fileupd.c new file mode 100644 index 0000000..3470e0a --- /dev/null +++ b/pw/fileupd.c @@ -0,0 +1,159 @@ +/*- + * Copyright (c) 1996 by David L. Nugent . + * 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 as + * the first lines of this file unmodified. + * 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 David L. Nugent. + * 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 DAVID L. NUGENT ``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 DAVID L. NUGENT 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. + * + * $Id$ + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pwupd.h" + +int +fileupdate(char const * filename, mode_t fmode, char const * newline, char const * prefix, int pfxlen, int updmode) +{ + int rc = 0; + + if (pfxlen <= 1) + errno = EINVAL; + else { + int infd = open(filename, O_RDWR | O_CREAT | O_EXLOCK, fmode); + + if (infd != -1) { + FILE *infp = fdopen(infd, "r+"); + + if (infp == NULL) + close(infd); + else { + int outfd; + char file[MAXPATHLEN]; + + strcpy(file, filename); + strcat(file, ".new"); + outfd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, fmode); + if (outfd != -1) { + FILE *outfp = fdopen(outfd, "w+"); + + if (outfp == NULL) + close(outfd); + else { + int updated = UPD_CREATE; + char line[2048]; + + while (fgets(line, sizeof(line), infp) != NULL) { + char *p = strchr(line, '\n'); + + if (p == NULL) { /* Line too long */ + int ch; + + fputs(line, outfp); + while ((ch = fgetc(infp)) != EOF) { + fputc(ch, outfp); + if (ch == '\n') + break; + } + continue; + } + if (*line != '#' && *line != '\n') { + if (!updated && strncmp(line, prefix, pfxlen) == 0) { + updated = updmode == UPD_REPLACE ? UPD_REPLACE : UPD_DELETE; + + /* + * Only actually write changes if updating + */ + if (updmode == UPD_REPLACE) + strcpy(line, newline); + else if (updmode == UPD_DELETE) + continue; + } + } + fputs(line, outfp); + } + + /* + * Now, we need to decide what to do: If we are in + * update mode, and no record was updated, then error If + * we are in insert mode, and record already exists, + * then error + */ + if (updmode != updated) + errno = (updmode == UPD_CREATE) ? EEXIST : ENOENT; + else { + + /* + * If adding a new record, append it to the end + */ + if (updmode == UPD_CREATE) + fputs(newline, outfp); + + /* + * Flush the file and check for the result + */ + rc = fflush(outfp) != EOF; + if (rc) { + + /* + * Copy data back into the + * original file and truncate + */ + rewind(infp); + rewind(outfp); + while (fgets(line, sizeof(line), outfp) != NULL) + fputs(line, infp); + + /* + * This is a gross hack, but we may have + * corrupted the original file + * Unfortunately, it will lose the inode. + */ + if (fflush(infp) == EOF || ferror(infp)) + rc = rename(file, filename) == 0; + else + ftruncate(infd, ftell(infp)); + } + } + fclose(outfp); + } + remove(file); + } + fclose(infp); + } + } + } + return rc; +} -- cgit v1.2.3-56-ge451