first commit

1 files changed, 58 insertions, 0 deletions

diff --git a/src/tac.c b/src/tac.c
new file mode 100644
index 0000000..3f7caf6
--- /dev/null
+++ b/src/tac.c
@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define PROGRAM_NAME "tac"
+
+struct stat statbuf;
+
+int main(int argc, char* argv[]) {
+	FILE *fileptr = NULL;
+	char buf[8192];
+	char ch;
+	int size = 0;
+
+	if (argc < 2) {
+		while (fgets(buf, sizeof(buf), stdin) != NULL) {
+			printf("%s", buf);
+		}
+
+		return 0;
+	}	
+
+	if (access(argv[1], F_OK) != 0) {
+		printf("%s: %s: No such file or directory.\n", PROGRAM_NAME, argv[1]);
+		return 1;
+	}
+		
+	if (stat(argv[1], &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
+		printf("%s: %s is a directory.\n", PROGRAM_NAME, argv[1]);
+		return 1;
+	}
+
+	fileptr = fopen(argv[1], "r");
+	
+	if (fileptr == NULL) {
+		perror("tac");
+		return 1;
+	}
+
+	while ((ch = fgetc(fileptr)) != EOF) {
+		size++;
+	}
+		
+	size = size - 2;
+	rewind(fileptr);
+
+	while (size >= 0) {
+		fseek(fileptr, size, 0);
+		ch = fgetc(fileptr);
+		putchar(ch);
+		size--;
+	}
+
+	printf("\n");
+
+	fclose(fileptr);
+	return 0;
+}