X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fnoerr%2F_info;fp=ccan%2Fnoerr%2F_info;h=fee413d3bbc90b23a756bc3a1b7eefb8a1c019e0;hp=0000000000000000000000000000000000000000;hb=570c9c555f076e74f46141bb42b5d1d7ac89f632;hpb=8f61c0bccb152b2365baf70deac1e59264d7feb7

diff --git a/ccan/noerr/_info b/ccan/noerr/_info
new file mode 100644
index 00000000..fee413d3
--- /dev/null
+++ b/ccan/noerr/_info
@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * noerr - routines for cleaning up without blatting errno
+ *
+ * It is a good idea to follow the standard C convention of setting errno in
+ * your own helper functions.  Unfortunately, care must be taken in the error
+ * paths as most standard functions can (and do) overwrite errno, even if they
+ * succeed.
+ *
+ * Example:
+ *	#include <sys/types.h>
+ *	#include <sys/stat.h>
+ *	#include <fcntl.h>
+ *	#include <stdbool.h>
+ *	#include <string.h>
+ *	#include <errno.h>
+ *	#include <ccan/noerr/noerr.h>
+ *
+ *	bool write_string_to_file(const char *file, const char *string)
+ *	{
+ *		int ret, fd = open(file, O_WRONLY|O_CREAT|O_EXCL, 0600);
+ *		if (fd < 0)
+ *			return false;
+ *		ret = write(fd, string, strlen(string));
+ *		if (ret < 0) {
+ *			// Preserve errno from write above.
+ *			close_noerr(fd);
+ *			unlink_noerr(file);
+ *			return false;
+ *		}
+ *		if (close(fd) != 0) {
+ *			// Again, preserve errno.
+ *			unlink_noerr(file);
+ *			return false;
+ *		}
+ *		// A short write means out of space.
+ *		if (ret < strlen(string)) {
+ *			unlink(file);
+ *			errno = ENOSPC;
+ *			return false;
+ *		}
+ *		return true;
+ *	}
+ *
+ * Licence: LGPL (2 or any later version)
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0)
+		/* Nothing. */
+		return 0;
+
+	return 1;
+}