decouple delgroup and deluser

1 files changed, 113 insertions, 0 deletions

diff --git a/loginutils/delline.c b/loginutils/delline.c
new file mode 100644
index 0000000..ed29ca0
--- /dev/null
+++ b/loginutils/delline.c
@@ -0,0 +1,113 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * deluser (remove lusers from the system ;) for TinyLogin
+ *
+ * Copyright (C) 1999 by Lineo, inc. and John Beppu
+ * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "busybox.h"
+
+
+
+/* where to start and stop deletion */
+typedef struct {
+	size_t start;
+	size_t stop;
+} Bounds;
+
+/* An interesting side-effect of boundary()'s
+ * implementation is that the first user (typically root)
+ * cannot be removed.  Let's call it a feature. */
+static inline Bounds boundary(const char *buffer, const char *login)
+{
+	char needle[256];
+	char *start;
+	char *stop;
+	Bounds b;
+
+	snprintf(needle, 256, "\n%s:", login);
+	needle[255] = 0;
+	start = strstr(buffer, needle);
+	if (!start) {
+		b.start = 0;
+		b.stop = 0;
+		return b;
+	}
+	start++;
+
+	stop = index(start, '\n');	/* index is a BSD-ism */
+	b.start = start - buffer;
+	b.stop = stop - buffer;
+	return b;
+}
+
+/* grep -v ^login (except it only deletes the first match) */
+/* ...in fact, I think I'm going to simplify this later */
+static int del_line_matching(const char *login, const char *filename)
+{
+	char *buffer;
+	FILE *passwd;
+	size_t len;
+	Bounds b;
+	struct stat statbuf;
+
+	/* load into buffer */
+	passwd = fopen(filename, "r");
+	if (!passwd) {
+		return 1;
+	}
+	stat(filename, &statbuf);
+	len = statbuf.st_size;
+	buffer = (char *) malloc(len * sizeof(char));
+
+	if (!buffer) {
+		fclose(passwd);
+		return 1;
+	}
+	fread(buffer, len, sizeof(char), passwd);
+
+	fclose(passwd);
+
+	/* find the user to remove */
+	b = boundary(buffer, login);
+	if (b.stop == 0) {
+		free(buffer);
+		return 1;
+	}
+
+	/* write the file w/o the user */
+	passwd = fopen(filename, "w");
+	if (!passwd) {
+		return 1;
+	}
+	fwrite(buffer, (b.start - 1), sizeof(char), passwd);
+	fwrite(&buffer[b.stop], (len - b.stop), sizeof(char), passwd);
+
+	fclose(passwd);
+
+	return 0;
+}
+
+
+/* $Id: delline.c,v 1.1 2003/07/14 20:20:45 andersen Exp $ */