From 6986963b4bd8a03263e3631c2b4e58a3877ead20 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Tue, 22 Nov 2011 17:57:10 +0100
Subject: [PATCH] cp(1) can now support the syntax cp /bin/snake /

---
 utils/cp.cpp | 39 +++++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/utils/cp.cpp b/utils/cp.cpp
index 3a8db821..974235ca 100644
--- a/utils/cp.cpp
+++ b/utils/cp.cpp
@@ -18,23 +18,50 @@ bool writeall(int fd, const void* buffer, size_t len)
 	return true;
 }
 
+const char* basename(const char* path)
+{
+	size_t len = strlen(path);
+	while ( len-- ) { if ( path[len] == '/' ) { return path + len + 1; } }
+	return path;
+}
+
 int main(int argc, char* argv[])
 {
 	if ( argc != 3 ) { printf("usage: %s <from> <to>\n", argv[0]); return 0; }
 
-	int fromfd = open(argv[1], O_RDONLY);
-	if ( fromfd < 0 ) { printf("%s: %s: %s\n", argv[0], argv[1], strerror(errno)); return 1; }
+	const char* frompath = argv[1];
+	const char* topath = argv[2];
+	char tobuffer[256];
 
-	int tofd = open(argv[2], O_WRONLY | O_TRUNC | O_CREAT, 0777);
-	if ( tofd < 0 ) { printf("%s: %s: %s\n", argv[0], argv[2], strerror(errno)); return 1; }
+	int fromfd = open(frompath, O_RDONLY);
+	if ( fromfd < 0 ) { printf("%s: %s: %s\n", argv[0], frompath, strerror(errno)); return 1; }
+
+	int tofd = open(topath, O_WRONLY | O_TRUNC | O_CREAT, 0777);
+	if ( tofd < 0 )
+	{
+		if ( errno == EISDIR )
+		{
+			strcpy(tobuffer, topath);
+			if ( tobuffer[strlen(tobuffer)-1] != '/' ) { strcat(tobuffer, "/"); }
+			strcat(tobuffer, basename(frompath));
+			topath = tobuffer;
+			tofd = open(topath, O_WRONLY | O_TRUNC | O_CREAT, 0777);
+		}
+
+		if ( tofd < 0 )
+		{
+			printf("%s: %s: %s\n", argv[0], topath, strerror(errno));
+			return 1;
+		}
+	}
 
 	while ( true )
 	{
 		const size_t BUFFER_SIZE = 4096;
 		char buffer[BUFFER_SIZE];
 		ssize_t bytesread = read(fromfd, buffer, BUFFER_SIZE);
-		if ( bytesread < 0 ) { printf("%s: %s: %s\n", argv[0], argv[1], strerror(errno)); return 1; }
+		if ( bytesread < 0 ) { printf("%s: %s: %s\n", argv[0], frompath, strerror(errno)); return 1; }
 		if ( bytesread == 0 ) { return 0; }
-		if ( !writeall(tofd, buffer, bytesread) ) { printf("%s: %s: %s\n", argv[0], argv[2], strerror(errno)); return 1; }
+		if ( !writeall(tofd, buffer, bytesread) ) { printf("%s: %s: %s\n", argv[0], topath, strerror(errno)); return 1; }
 	}
 }