Add sort

apps/sort.c

@@ -0,0 +1,100 @@
+/* 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
+ *
+ * sort - Sort standard in or files.
+ *
+ * Currently implemented with a naive insertion sort.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <getopt.h>
+#include <errno.h>
+#include <ctype.h>
+#include <toaru/list.h>
+
+int compare(const char * a, const char * b) {
+	while (1) {
+		while (*a == *b || tolower(*a) == tolower(*b)) {
+			if (!*a) return 0;
+			a++;
+			b++;
+		}
+
+		while (*a && !isalnum(*a)) a++;
+		while (*b && !isalnum(*b)) b++;
+
+		if (tolower(*a) == tolower(*b)) continue;
+
+		if (tolower(*a) < tolower(*b)) return -1;
+		return 1;
+	}
+}
+
+int main(int argc, char * argv[]) {
+	int reverse = 0;
+	int opt;
+
+	list_t * lines = list_create();
+	list_t * files = list_create();
+
+	while ((opt = getopt(argc, argv, "r")) != -1) {
+		switch (opt) {
+			case 'r':
+				reverse = 1;
+				break;
+		}
+	}
+
+	if (optind == argc) {
+		/* No arguments */
+		list_insert(files, stdin);
+	} else {
+		while (optind < argc) {
+			FILE * f = fopen(argv[optind], "r");
+			if (!f) {
+				fprintf(stderr, "%s: %s: %s\n", argv[0], argv[optind], strerror(errno));
+			} else {
+				list_insert(files, f);
+			}
+			optind++;
+		}
+	}
+
+	char line_buf[4096] = {0};
+	foreach (node, files) {
+		FILE * f = node->value;
+		while (!feof(f)) {
+			if (!fgets(line_buf, 4096, f)) {
+				break;
+			}
+			if (!strchr(line_buf,'\n')) {
+				fprintf(stderr, "%s: oversized line\n", argv[0]);
+			}
+			char * line = strdup(line_buf);
+			node_t * next = NULL;
+			foreach (lnode, lines) {
+				char * cmp = lnode->value;
+				if (reverse ? (compare(cmp, line) < 0) : (compare(line, cmp) < 0)) {
+					next = lnode;
+					break;
+				}
+			}
+			if (next) {
+				list_insert_before(lines, next, line);
+			} else {
+				list_insert(lines, line);
+			}
+		}
+	}
+
+	foreach (lnode, lines) {
+		char * line = lnode->value;
+		fprintf(stdout, "%s", line);
+	}
+
+	return 0;
+}