From 41a2130487e6096ec9f3cecbfc90f4c2d0169ec1 Mon Sep 17 00:00:00 2001
From: Timothy Elliott <tle@holymonkey.com>
Date: Mon, 6 Feb 2012 17:35:59 -0800
Subject: Implement head
---
toys/head.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
toys/nice.c | 2 --
2 files changed, 62 insertions(+), 2 deletions(-)
create mode 100644 toys/head.c
(limited to 'toys')
diff --git a/toys/head.c b/toys/head.c
new file mode 100644
index 00000000..8f0baa24
--- /dev/null
+++ b/toys/head.c
@@ -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 --git a/toys/nice.c b/toys/nice.c
index 2fda2675..fa059bbd 100644
--- a/toys/nice.c
+++ b/toys/nice.c
@@ -24,8 +24,6 @@ config NICE
#include "toys.h"
-// Hello doesn't use these globals, they're here for example/skeleton purposes.
-
DEFINE_GLOBALS(
long priority;
)
--
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