# HG changeset patch
# User Timothy Elliott <tle@holymonkey.com>
# Date 1328578559 28800
# Node ID d3ca5e15e4572a94e1cddc3a7b872a9cbb7ef1b7
# Parent  41b5ac08208f89571365fb536d5775a07d4b73d7
Implement head

diff -r 41b5ac08208f -r d3ca5e15e457 toys/head.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/head.c	Mon Feb 06 17:35:59 2012 -0800
@@ -0,0 +1,62 @@
+/* vi: set sw=4 ts=4:
+ *
+ * head.c - copy first lines from input to stdout.
+ *
+ * Copyright 2006 Timothy Elliott <tle@holymonkey.com>
+ *
+ * See http://www.opengroup.org/onlinepubs/009695399/utilities/head.html
+
+USE_HEAD(NEWTOY(head, "n#", TOYFLAG_BIN))
+
+config HEAD
+	bool "head"
+	default y
+	help
+	  usage: head [-n number] [file...]
+	  Copy first lines from files to stdout. If no files listed, copy from
+	  stdin. Filename "-" is a synonym for stdin.
+
+	  -n	Number of lines to copy.
+*/
+
+#include "toys.h"
+
+DEFINE_GLOBALS(
+	long lines;
+	int file_no;
+)
+
+#define TT this.head
+
+static void do_head(int fd, char *name)
+{
+	int i, len, lines=TT.lines, size=sizeof(toybuf);
+
+	if (toys.optc > 1) {
+		// Print an extra newline for all but the first file
+		if (TT.file_no++ > 0) printf("\n");
+		printf("==> %s <==\n", name);
+	}
+
+	for (;lines>0;) {
+		len = read(fd, toybuf, size);
+		if (len<0) {
+			perror_msg("%s",name);
+			toys.exitval = EXIT_FAILURE;
+		}
+		if (len<1) break;
+		
+		for(i=0; i<len; i++) {
+			if (toybuf[i] == '\n' && --lines < 1) break;
+		}
+		xwrite(1, toybuf, i+1);
+	}
+}
+
+void head_main(void)
+{
+	if (!toys.optflags) TT.lines = 10;
+	if (TT.lines < 0) perror_exit("Invalid number of lines.");
+	TT.file_no = 0;
+	loopfiles(toys.optargs, do_head);
+}
diff -r 41b5ac08208f -r d3ca5e15e457 toys/nice.c
--- a/toys/nice.c	Thu Feb 09 06:09:27 2012 -0600
+++ b/toys/nice.c	Mon Feb 06 17:35:59 2012 -0800
@@ -24,8 +24,6 @@
 
 #include "toys.h"
 
-// Hello doesn't use these globals, they're here for example/skeleton purposes.
-
 DEFINE_GLOBALS(
 	long priority;
 )