Add tee

apps/tee.c

@@ -0,0 +1,60 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ * This file is part of ToaruOS and is released under the terms
+ * of the NCSA / University of Illinois License - see LICENSE.md
+ * Copyright (C) 2018 K. Lange
+ *
+ * tee - copy stdin to stdout and to specified files
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+
+int main(int argc, char * argv[]) {
+	int append = 0;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "ai")) != -1) {
+		switch (opt) {
+			case 'a':
+				append = 1;
+				break;
+			case 'i':
+				signal(SIGINT, SIG_IGN);
+				break;
+		}
+	}
+
+	int file_count = argc - optind;
+	FILE ** files = malloc(sizeof(FILE *) * file_count);
+
+	for (int i = 0, j = optind; j < argc && i < file_count; j++) {
+		files[i] = fopen(argv[j], append ? "a" : "w");
+		if (!files[i]) {
+			fprintf(stderr, "%s: %s: %s\n", argv[0], argv[j], strerror(errno));
+			file_count--;
+			continue;
+		} else {
+			i++;
+		}
+	}
+
+	while (!feof(stdin)) {
+		int c = fgetc(stdin);
+		if (c >= 0) {
+			fputc(c, stdout);
+
+			for (int i = 0; i < file_count; ++i) {
+				fputc(c, files[i]);
+			}
+		}
+	}
+
+	for (int i = 0; i < file_count; ++i) {
+		fclose(files[i]);
+	}
+
+	return 0;
+}