cat: Use ArgumentParser

apps/CMakeLists.txt

@@ -7,9 +7,11 @@ function(luna_app SOURCE_FILE APP_NAME)
 endfunction()
 
 luna_app(init.cpp init)
-luna_app(cat.cpp cat)
 luna_app(sh.cpp sh)
 
+luna_app(cat.cpp cat)
+target_link_libraries(cat PRIVATE os)
+
 luna_app(date.cpp date)
 target_link_libraries(date PRIVATE os)
 

apps/cat.cpp

@@ -1,9 +1,24 @@
+#include <os/ArgumentParser.h>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-static void do_cat(FILE* f)
+static void do_cat(StringView path)
 {
+    FILE* f;
+
+    if (path == "-") f = stdin;
+    else
+    {
+        f = fopen(path.chars(), "r");
+        if (!f)
+        {
+            perror(path.chars());
+            exit(1);
+        }
+    }
+
     char buffer[4096];
 
     while (1)
@@ -12,30 +27,19 @@ static void do_cat(FILE* f)
         if (nread == 0) return;
         fwrite(buffer, 1, nread, stdout);
     }
+
+    if (f != stdin) fclose(f);
 }
 
 int main(int argc, char** argv)
 {
-    FILE* f;
+    StringView filename;
 
-    if (argc < 2) { do_cat(stdin); }
-    else
-    {
-        for (int i = 1; i < argc; i++)
-        {
-            if (!strcmp(argv[i], "-")) f = stdin;
-            else
-            {
-                f = fopen(argv[i], "r");
-                if (!f)
-                {
-                    perror(argv[i]);
-                    return 1;
-                }
-            }
+    ArgumentParser parser;
+    parser.add_positional_argument(filename, "file"_sv, "-"_sv);
+    Vector<StringView> extra_files = parser.parse(argc, argv).value();
 
-            do_cat(f);
-            if (f != stdin) fclose(f);
-        }
-    }
+    do_cat(filename);
+
+    for (auto file : extra_files) { do_cat(file); }
 }