core/: cmp

Signed-off-by: Ferass El Hafidi <vitali64pmemail@protonmail.com>

2 files changed, 55 insertions, 0 deletions

diff --git a/config.mk b/config.mk
index 1585b79..7837b3b 100644
--- a/config.mk
+++ b/config.mk
@@ -14,6 +14,7 @@ CORE=\
 	cat\
 	chmod\
 	chown\
+	cmp\
 	date\
 	dirname\
 	echo\
diff --git a/core/cmp.c b/core/cmp.c
new file mode 100644
index 0000000..424b595
--- /dev/null
+++ b/core/cmp.c
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+/* Requirements in common.h */
+#define REQ_PRINT_USAGE
+#define REQ_ERRPRINT 
+#include "../common/common.h"
+
+#define DESCRIPTION "Compare two files."
+#define OPERANDS    "[-l|-s] file1 file2"
+
+int main(int argc, char *argv[]) {
+	FILE *file1, *file2;
+	int argument, char_pos = 1, line_pos = 1, param_l, param_s, differ;
+	char *argv0 = strdup(argv[0]), ch1, ch2;
+
+	while ((argument = getopt(argc, argv, "ls")) != -1) {
+		if (argument == '?')
+			return print_usage(argv0, DESCRIPTION, OPERANDS, VERSION);
+		else if (argument == 'l') param_l = 1;
+		else if (argument == 's') param_s = 1;
+	} argc -= optind; argv += optind;
+	if (argc != 2) return print_usage(argv0, DESCRIPTION, OPERANDS, VERSION);
+
+	/* Open the files. */
+	file1 = fopen(argv[0], "r");
+	file2 = fopen(argv[1], "r");
+	if (file1 == NULL)
+		return errprint(argv0, argv[0], errno);
+	else if (file2 == NULL)
+		return errprint(argv0, argv[1], errno);
+
+	/* Compare! */
+	while ((ch1 = fgetc(file1)) && (ch2 = fgetc(file2))) {
+		if (ch1 == -1 || ch2 == -1) {
+			return errprint(argv0, "fgetc()", errno);
+		} else if (ch1 != ch2) {
+			differ = 1;
+			if (param_l)
+				printf("%d %o %o\n", char_pos, ch1, ch2);
+			else if (!param_s)
+				printf("%s %s differ: char %d, line %d\n", argv[0], argv[1], 
+					char_pos, line_pos);
+			if (!param_l) break;
+		}
+		if (ch1 == '\n' && ch2 == '\n')
+			line_pos++;
+		char_pos++;
+	}
+	return differ;
+}