Userland: Move command-line utilities to Userland/Utilities/

Userland/Utilities/uniq.cpp

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2020, Matthew L. Curry <matthew.curry@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/RefPtr.h>
+#include <LibCore/ArgsParser.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct linebuf {
+    char* buf = NULL;
+    size_t len = 0;
+};
+
+static FILE* get_stream(const char* filepath, const char* perms)
+{
+    FILE* ret;
+
+    if (filepath == nullptr) {
+        if (perms[0] == 'r')
+            return stdin;
+        return stdout;
+    }
+
+    ret = fopen(filepath, perms);
+    if (ret == nullptr) {
+        perror("fopen");
+        exit(1);
+    }
+
+    return ret;
+}
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio rpath wpath cpath", nullptr) > 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    const char* inpath = nullptr;
+    const char* outpath = nullptr;
+    Core::ArgsParser args_parser;
+    args_parser.add_positional_argument(inpath, "Input file", "input", Core::ArgsParser::Required::No);
+    args_parser.add_positional_argument(outpath, "Output file", "output", Core::ArgsParser::Required::No);
+    args_parser.parse(argc, argv);
+
+    FILE* infile = get_stream(inpath, "r");
+    FILE* outfile = get_stream(outpath, "w");
+
+    struct linebuf buffers[2];
+    struct linebuf* previous = &(buffers[0]);
+    struct linebuf* current = &(buffers[1]);
+    bool first_run = true;
+    for (;;) {
+        errno = 0;
+        ssize_t rc = getline(&(current->buf), &(current->len), infile);
+        if (rc < 0 && errno != 0) {
+            perror("getline");
+            exit(1);
+        }
+        if (rc < 0)
+            break;
+        if (!first_run && strcmp(current->buf, previous->buf) == 0)
+            continue;
+
+        fputs(current->buf, outfile);
+        AK::swap(current, previous);
+        first_run = false;
+    }
+
+    fclose(infile);
+    fclose(outfile);
+
+    return 0;
+}