1 files changed, 77 insertions, 0 deletions
diff --git a/util/sbase/head.c b/util/sbase/head.c
new file mode 100644
index 00000000..ae550c01
--- /dev/null
+++ b/util/sbase/head.c
@@ -0,0 +1,77 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+
+static void
+head(FILE *fp, const char *fname, size_t n)
+{
+	char *buf = NULL;
+	size_t i = 0, size = 0;
+	ssize_t len;
+
+	while (i < n && (len = getline(&buf, &size, fp)) > 0) {
+		fwrite(buf, 1, len, stdout);
+		i += (len && (buf[len - 1] == '\n'));
+	}
+	free(buf);
+	if (ferror(fp))
+		eprintf("getline %s:", fname);
+}
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-num | -n num] [file ...]\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	size_t n = 10;
+	FILE *fp;
+	int ret = 0, newline = 0, many = 0;
+
+	ARGBEGIN {
+	case 'n':
+		n = estrtonum(EARGF(usage()), 0, MIN(LLONG_MAX, SIZE_MAX));
+		break;
+	ARGNUM:
+		n = ARGNUMF();
+		break;
+	default:
+		usage();
+	} ARGEND
+
+	if (!argc) {
+		head(stdin, "<stdin>", n);
+	} else {
+		many = argc > 1;
+		for (newline = 0; *argv; argc--, argv++) {
+			if (!strcmp(*argv, "-")) {
+				*argv = "<stdin>";
+				fp = stdin;
+			} else if (!(fp = fopen(*argv, "r"))) {
+				weprintf("fopen %s:", *argv);
+				ret = 1;
+				continue;
+			}
+			if (many) {
+				if (newline)
+					putchar('\n');
+				printf("==> %s <==\n", *argv);
+			}
+			newline = 1;
+			head(fp, *argv, n);
+			if (fp != stdin && fshut(fp, *argv))
+				ret = 1;
+		}
+	}
+
+	ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
+
+	return ret;
+}