1 files changed, 59 insertions, 0 deletions
diff --git a/fallocate.c b/fallocate.c
new file mode 100644
index 0000000..910d191
--- /dev/null
+++ b/fallocate.c
@@ -0,0 +1,59 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+#define EXIT_BAD_OPTION 2
+
+
+void usage(int fd, char * progname)
+{
+	dprintf(fd, "Usage: %s [-o offset] -l length name\n", progname);
+}
+
+
+int try_fallocate(char * filename, int offset, int length)
+{
+	int fd = open(filename, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+	if (-1 == fd) return -1;
+	int res = posix_fallocate(fd, offset, length);
+	if (-1 == res) return -1;
+	res = close(fd);
+	if (-1 == res) return -1;
+	return 0;
+}
+
+
+int main(int argc, char * argv[])
+{
+	int opt;
+	int offset = 0;
+	int length = 0;
+	char * filename;
+	while (-1 != (opt = getopt(argc, argv, "o:l:"))) {
+		switch (opt) {
+		case 'o':
+			offset = atoi(optarg);
+			break;
+		case 'l':
+			length = atoi(optarg);
+			break;
+		default:
+			usage(2, argv[0]);
+			exit(EXIT_BAD_OPTION);
+		}
+	}
+	if (0 >= length || argc <= optind) {
+		usage(2, argv[0]);
+		exit(EXIT_BAD_OPTION);
+	}
+	filename = argv[optind];
+	int res = try_fallocate(filename, offset, length);
+	if (-1 == res) {
+		dprintf(2, "%s: %s: %s\n", argv[0], filename, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+}