1 files changed, 138 insertions, 0 deletions

diff --git a/busybox/coreutils/head.c b/busybox/coreutils/head.c
new file mode 100644
index 000000000..dab4de11b
--- /dev/null
+++ b/busybox/coreutils/head.c
@@ -0,0 +1,138 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * head implementation for busybox
+ *
+ * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <ctype.h>
+#include <unistd.h>
+#include "busybox.h"
+
+static const char head_opts[] =
+        "n:"
+#ifdef CONFIG_FEATURE_FANCY_HEAD
+        "c:qv"
+#endif
+        ;
+
+static const char header_fmt_str[] = "\n==> %s <==\n";
+
+int head_main(int argc, char **argv)
+{
+        unsigned long count = 10;
+        unsigned long i;
+#ifdef CONFIG_FEATURE_FANCY_HEAD
+        int count_bytes = 0;
+        int header_threshhold = 1;
+#endif
+
+        FILE *fp;
+        const char *fmt;
+        char *p;
+        int opt;
+        int c;
+        int retval = EXIT_SUCCESS;
+
+        /* Allow legacy syntax of an initial numeric option without -n. */
+        if ((argc > 1) && (argv[1][0] == '-')
+                /* && (isdigit)(argv[1][1]) */
+                && (((unsigned int)(argv[1][1] - '0')) <= 9)
+        ) {
+                --argc;
+                ++argv;
+                p = (*argv) + 1;
+                goto GET_COUNT;
+        }
+
+        while ((opt = getopt(argc, argv, head_opts)) > 0) {
+                switch(opt) {
+#ifdef CONFIG_FEATURE_FANCY_HEAD
+                        case 'q':
+                                header_threshhold = INT_MAX;
+                                break;
+                        case 'v':
+                                header_threshhold = -1;
+                                break;
+                        case 'c':
+                                count_bytes = 1;
+                                /* fall through */
+#endif
+                        case 'n':
+                                p = optarg;
+                        GET_COUNT:
+                                count = bb_xgetularg10(p);
+                                break;
+                        default:
+                                bb_show_usage();
+                }
+        }
+
+        argv += optind;
+        if (!*argv) {
+                *--argv = "-";
+        }
+
+        fmt = header_fmt_str + 1;
+#ifdef CONFIG_FEATURE_FANCY_HEAD
+        if (argc - optind <= header_threshhold) {
+                header_threshhold = 0;
+        }
+#else
+        if (argc <= optind + 1) {
+                fmt += 11;
+        }
+        /* Now define some things here to avoid #ifdefs in the code below.
+         * These should optimize out of the if conditions below. */
+#define header_threshhold   1
+#define count_bytes         0
+#endif
+
+        do {
+                if ((fp = bb_wfopen_input(*argv)) != NULL) {
+                        if (fp == stdin) {
+                                *argv = (char *) bb_msg_standard_input;
+                        }
+                        if (header_threshhold) {
+                                bb_printf(fmt, *argv);
+                        }
+                        i = count;
+                        while (i && ((c = getc(fp)) != EOF)) {
+                                if (count_bytes || (c == '\n')) {
+                                        --i;
+                                }
+                                putchar(c);
+                        }
+                        if (bb_fclose_nonstdin(fp)) {
+                                bb_perror_msg("%s", *argv);     /* Avoid multibyte problems. */
+                                retval = EXIT_FAILURE;
+                        }
+                        bb_xferror_stdout();
+                }
+                fmt = header_fmt_str;
+        } while (*++argv);
+
+        bb_fflush_stdout_and_exit(retval);
+}