outline C program

2 files changed, 45 insertions, 0 deletions

diff --git a/tac b/tac
deleted file mode 100644
index e69de29..0000000
--- a/tac
+++ /dev/null
diff --git a/tac.c b/tac.c
new file mode 100644
index 0000000..088ebda
--- /dev/null
+++ b/tac.c
@@ -0,0 +1,45 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct line {
+	struct line *prev;
+	struct line *next;
+	char *line;
+};
+
+int tac(const char *path)
+{
+	FILE *f = stdin;
+	if (path && strcmp(path, "-") != 0) {
+		f = fopen(path, "r");
+		if (f == NULL) {
+			perror("tac:fopen");
+		}
+	}
+
+	/* read lines into doubly-linked list */
+	/* print lines in reverse order */
+
+	if (f != stdin) {
+		fclose(f);
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	while (getopt(argc, argv, "") != -1) {
+		/* no options supported */
+		return 1;
+	}
+
+	int ret = 0;
+	do {
+		ret |= tac(argv[optind]);
+	} while (argv[++optind]);
+	return 1;
+}