From 6b9edb2946fff8177ce9b1a8944b762101dda2ae Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Fri, 17 Nov 2023 15:29:29 +0300
Subject: [PATCH] head add, uname fix

---
 config.h          |   3 ++
 coreutils/head.c  |  93 ++++++++++++++++++++++++++++++++++++++++++
 coreutils/uname.c | 100 +++++++++++++++++++---------------------------
 3 files changed, 138 insertions(+), 58 deletions(-)
 create mode 100644 coreutils/head.c

diff --git a/config.h b/config.h
index 06641aa..813abef 100644
--- a/config.h
+++ b/config.h
@@ -7,6 +7,9 @@
 /* Random source for shred */
 #define RAND_SOURCE "/dev/urandom"
 
+/* format for printf (head) */
+#define HEAD_FMT "==> %s <==\n"
+
 /* Options: To disable, comment line */
 /* Add escape-char support in echo */
 #define ECHO_FANCY
diff --git a/coreutils/head.c b/coreutils/head.c
new file mode 100644
index 0000000..385c2e5
--- /dev/null
+++ b/coreutils/head.c
@@ -0,0 +1,93 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "config.h"
+
+unsigned int v_flag;
+unsigned int c_flag;
+
+long parse_long(const char *str) {
+	char *ptr;
+	long ret = strtol(str, &ptr, 0);
+	if (*ptr) {
+		fprintf(stderr, "head: %s invalid number\n", ptr);
+		exit(1);
+	}
+
+	return ret;
+}
+
+void print(const char *file, FILE *fp, long lines, long bytes) {
+	if (v_flag)
+		printf(HEAD_FMT, file);
+
+	long lcount = 0;
+	long bcount = 0;
+
+	while (1) {
+		int c = getc(fp);
+		if (c == EOF || lcount == lines || (c_flag && bcount == bytes))
+			break;
+
+		if (c == '\n')
+			lcount++;
+
+		bcount++;
+		putchar(c);
+	}
+}
+
+int main(int argc, char **argv) {
+	long lines = 10;
+	long bytes = 0;
+
+	int opt;
+	while ((opt = getopt(argc, argv, "n:c:v")) != -1) {
+		switch (opt) {
+			case 'n':
+				lines = parse_long(optarg);
+				break;
+
+			case 'c':
+				c_flag = 1;
+				bytes = parse_long(optarg);
+				break;
+
+			case 'v':
+				v_flag = 1;
+				break;
+
+			default:
+				printf("head [file1 file2...]\n\t[-n Print N lines] [-c Print N bytes]\n\t[-v Print headers]\n");
+				return 0;
+		}
+	}
+
+	argv += optind;
+	argc -= optind;
+
+	if (argc == 0)
+		print("-", stdin, lines, bytes);
+
+	for (int i = 0; i < argc; i++) {
+		FILE *fp = NULL;
+		if (argv[i][0] == '-')
+			fp = stdin;
+
+		else
+			fp = fopen(argv[i], "r");
+
+		if (fp == NULL) {
+			fprintf(stderr, "head: %s: %s\n", argv[i], strerror(errno));
+			return 1;
+		}
+
+		print(argv[i], fp, lines, bytes);
+		fclose(fp);
+	}
+
+	return 0;
+}
diff --git a/coreutils/uname.c b/coreutils/uname.c
index 8c14d52..3abbedd 100644
--- a/coreutils/uname.c
+++ b/coreutils/uname.c
@@ -4,72 +4,56 @@
 #include <unistd.h>
 #include <sys/utsname.h>
 
-/* sys node release version machine */
-int flags[] = {0, 0, 0, 0, 0};
-enum {
-	O_SYS,
-	O_NODE,
-	O_RELEASE,
-	O_VERSION,
-	O_MACHINE,
-	O_ALL
-};
-
 int main(int argc, char **argv) {
-	int opt;
-	while ((opt = getopt(argc, argv, "ashrvm")) != -1) {
-		switch (opt) {
-			case 'a':
-				for (int i = 0; i < O_ALL; i++)
-					flags[i] = 1;
-				break;
-
-			case 's':
-				flags[O_SYS] = 1;
-				break;
-
-			case 'n':
-				flags[O_NODE] = 1;
-				break;
-
-			case 'r':
-				flags[O_RELEASE] = 1;
-				break;
-
-			case 'v':
-				flags[O_VERSION] = 1;
-				break;
-
-			case 'm':
-				flags[O_MACHINE] = 1;
-				break;
-
-			default:
-				printf("uname [-a All] [-s Sys] [-n Nodename] [-r Release] [-v Version] [-m Machine]\n");
-				return 0;
-		}
-	}
-
 	struct utsname uts;
 	if (uname(&uts)) {
 		fprintf(stderr, "uname: %s", strerror(errno));
 		return 1;
 	}
 
-	if (flags[O_SYS] || argc == 1)
+
+	unsigned int a_flag = 0;
+
+	int opt;
+	while ((opt = getopt(argc, argv, "ashrvm")) != -1) {
+		switch (opt) {
+			case 'a':
+				a_flag = 1;
+				/* fallthrough */
+
+			case 's':
+				printf("%s ", uts.sysname);
+				if (!a_flag)
+					break;
+
+			case 'n':
+				printf("%s ", uts.nodename);
+				if (!a_flag)
+					break;
+
+			case 'r':
+				printf("%s ", uts.release);
+				if (!a_flag)
+					break;
+
+			case 'v':
+				printf("%s ", uts.version);
+				if (!a_flag)
+					break;
+
+			case 'm':
+				printf("%s ", uts.machine);
+				break;
+
+			default:
+				printf("uname\n\t[-a All] [-s Sys]\n\t[-n Nodename] [-r Release]\n\t[-v Version] [-m Machine]\n");
+				return 0;
+		}
+	}
+
+	argc -= optind;
+	if (argc == 0)
 		printf("%s ", uts.sysname);
 
-	if (flags[O_NODE])
-		printf("%s ", uts.nodename);
-
-	if (flags[O_RELEASE])
-		printf("%s ", uts.release);
-
-	if (flags[O_VERSION])
-		printf("%s ", uts.version);
-
-	if (flags[O_MACHINE])
-		printf("%s ", uts.machine);
-
 	putchar('\n');
 }