summaryrefslogtreecommitdiffstats
path: root/lib/file/file.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/file/file.c')
-rw-r--r--lib/file/file.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/lib/file/file.c b/lib/file/file.c
new file mode 100644
index 0000000..1bde9fb
--- /dev/null
+++ b/lib/file/file.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2013 Jeremy Kerr <jk@ozlabs.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; version 2 of the License.
+ *
+ * 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 <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <talloc/talloc.h>
+
+#include "file.h"
+
+static const int max_file_size = 1024 * 1024;
+
+int read_file(void *ctx, const char *filename, char **bufp, int *lenp)
+{
+ struct stat statbuf;
+ int rc, fd, i, len;
+ char *buf;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ rc = fstat(fd, &statbuf);
+ if (rc < 0)
+ goto err_close;
+
+ len = statbuf.st_size;
+ if (len > max_file_size)
+ goto err_close;
+
+ buf = talloc_array(ctx, char, len + 1);
+ if (!buf)
+ goto err_close;
+
+ for (i = 0; i < len; i += rc) {
+ rc = read(fd, buf + i, len - i);
+
+ /* unexpected EOF: trim and return */
+ if (rc == 0) {
+ len = i;
+ break;
+ }
+
+ if (rc < 0)
+ goto err_free;
+
+ }
+
+ buf[len] = '\0';
+
+ close(fd);
+ *bufp = buf;
+ *lenp = len;
+ return 0;
+
+err_free:
+ talloc_free(buf);
+err_close:
+ close(fd);
+ return -1;
+}
+
+static int write_fd(int fd, char *buf, int len)
+{
+ int i, rc;
+
+ for (i = 0; i < len; i += rc) {
+ rc = write(fd, buf + i, len - i);
+ if (rc < 0 && errno != -EINTR)
+ return rc;
+ }
+
+ return 0;
+}
+
+int replace_file(const char *filename, char *buf, int len)
+{
+ char *tempfile;
+ mode_t oldmask;
+ int rc, fd;
+
+ tempfile = talloc_asprintf(NULL, "%s.XXXXXX", filename);
+
+ oldmask = umask(0644);
+ fd = mkstemp(tempfile);
+ umask(oldmask);
+ if (fd < 0) {
+ talloc_free(tempfile);
+ return fd;
+ }
+
+ rc = write_fd(fd, buf, len);
+ if (rc) {
+ unlink(tempfile);
+ } else {
+ rc = rename(tempfile, filename);
+ }
+
+ talloc_free(tempfile);
+
+ fchmod(fd, 0644);
+
+ close(fd);
+ return rc;
+}
OpenPOWER on IntegriCloud