From 90d49dd3cf07a4cabd50a07365860a02447b42df Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Tue, 17 Oct 2023 19:45:31 +0300
Subject: [PATCH] Mmmm...

---
 coreutils/cp.c | 64 ++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 51 insertions(+), 13 deletions(-)

diff --git a/coreutils/cp.c b/coreutils/cp.c
index 5d6689d..aff13d5 100644
--- a/coreutils/cp.c
+++ b/coreutils/cp.c
@@ -22,11 +22,25 @@ char *make_path(const char *src, const char *dst) {
 }
 
 int write_buffer(int ifd, int ofd) {
-	char buf[4096];
-	size_t bytes = 0;
-	while ((bytes = read(ifd, buf, sizeof(buf))) > 0)
-		if (write(ofd, buf, bytes) != bytes)
-			return 1;
+	off_t len = lseek(ifd, 0, SEEK_END);
+	if (len <= 0)
+		return 1;
+
+	if (ftruncate(ofd, len) < 0)
+		return 1;
+
+	void *buf_in = mmap(NULL, len, PROT_READ, MAP_SHARED, ifd, 0);
+	if (buf_in == MAP_FAILED)
+		return 1;
+
+	void *buf_out = mmap(NULL, len, PROT_WRITE, MAP_SHARED, ofd, 0);
+	if (buf_out == MAP_FAILED)
+		return 1;
+
+	memcpy(buf_out, buf_in, len);
+
+	if (munmap(buf_in, len) || munmap(buf_out, len))
+		return 1;
 
 	return 0;
 
@@ -37,7 +51,7 @@ int copy(const char *src, const char *dst) {
 	if (ifd < 0)
 		return 1;
 
-	int ofd = open(dst, O_CREAT | O_TRUNC | O_WRONLY, 0666);
+	int ofd = open(dst, O_CREAT | O_TRUNC | O_RDWR, 0644);
 	if (ofd < 0) {
 		close(ifd);
 		return 1;
@@ -62,7 +76,8 @@ int get_stat(const char *path, struct stat *stat_path) {
 
 int cptree(const char *src, const char *dst) {
 	struct stat stat_path;
-	get_stat(src, &stat_path);
+	if (get_stat(src, &stat_path))
+		return 1;
 
 	if (S_ISDIR(stat_path.st_mode) == 0) {
 		if (copy(src, dst)) {
@@ -73,9 +88,8 @@ int cptree(const char *src, const char *dst) {
 		return 0;
 	}
 
-	else if (mkdir(dst, 0777) < 0) {
+	else if (mkdir(dst, 0777) < 0)
 		fprintf(stderr, "cp: %s\n", strerror(errno));
-	}
 
 	DIR *dir = opendir(src);
 	if (dir == NULL) {
@@ -107,10 +121,34 @@ int cptree(const char *src, const char *dst) {
 }
 
 int main(const int argc, const char **argv) {
-	if (argc < 2 || !strcmp(argv[1], "-h")) {
-		printf("cp [Src] [Dst]\n");
-		return 0;
+
+	int i;
+	for (i = 1; i < argc; i++) {
+		if (argv[i][0] != '-')
+			break;
+
+		else if (!strcmp(argv[i], "-h")) {
+			printf("cp [Src] [Dst]\n");
+			return 0;
+		}
 	}
 
-	return cptree(argv[1], argv[2]);
+	int ret = 0;
+	if (argc - i == 2)
+		ret = cptree(argv[i], argv[argc - 1]);
+
+	else {
+		for (; i < argc - 1; i++) {
+			char *new_path = make_path(argv[argc - 1], basename(argv[i]));
+			if (new_path == NULL)
+				return 1;
+
+			if (copy(argv[i], new_path))
+				ret = 1;
+
+			free(new_path);
+		}
+	}
+
+	return ret;
 }