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, <davidn@blaze.net.au>

1 files changed, 159 insertions, 0 deletions

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 <davidn@blaze.net.au>.
+ * 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 <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <errno.h>
+#include <unistd.h>
+
+#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;
+}