fish_indent: Allow multiple file arguments

Allows `fish_indent -w **.fish` to restyle all fish files under the
current directory.

(This also has the sideeffect of reducing style.fish time by ~10s, as
we only need to invoke `fish_indent` once, instead of once per-file)

build_tools/style.fish

@@ -95,16 +95,7 @@ if set -q fish_files[1]
         set PATH . $PATH
     end
     echo === Running "$green"fish_indent"$normal"
-    for file in $fish_files
+    fish_indent -w -- $fish_files
-        cp $file $file.new # preserves mode bits
-        fish_indent <$file >$file.new
-        if cmp --quiet $file $file.new
-            rm $file.new
-        else
-            echo $file was NOT correctly formatted
-            mv $file.new $file
-        end
-    end
 end
 
 if set -q python_files[1]

sphinx_doc_src/cmds/fish_indent.rst

@@ -6,13 +6,13 @@ fish_indent - indenter and prettifier
 Synopsis
 --------
 
-fish_indent [OPTIONS]
+fish_indent [OPTIONS] [FILE...]
 
 
 Description
 -----------
 
-``fish_indent`` is used to indent a piece of fish code. ``fish_indent`` reads commands from standard input and outputs them to standard output or a specified file.
+``fish_indent`` is used to indent a piece of fish code. ``fish_indent`` reads commands from standard input or the given filenames and outputs them to standard output or a specified file (if `-w` is given).
 
 The following options are available:
 

src/fish_indent.cpp

@@ -629,25 +629,22 @@ int main(int argc, char *argv[]) {
             exit(1);
         }
         src = read_file(stdin);
-    } else if (argc == 1) {
+    } else {
-        FILE *fh = fopen(*argv, "r");
+        ret = EXIT_SUCCESS;
+        for (int i; i < argc; i++) {
+            FILE *fh = fopen(argv[i], "r");
             if (fh) {
                 src = read_file(fh);
                 fclose(fh);
-            output_location = *argv;
+                output_location = argv[i];
             } else {
                 std::fwprintf(stderr, _(L"Opening \"%s\" failed: %s\n"), *argv, std::strerror(errno));
                 exit(1);
             }
-    } else {
-        std::fwprintf(stderr, _(L"Too many arguments\n"));
-        exit(1);
-    }
 
             if (output_type == output_type_pygments_csv) {
                 std::string output = make_pygments_csv(src);
                 fputs(output.c_str(), stdout);
-        return EXIT_SUCCESS;
             }
 
             const wcstring output_wtext = prettify(src, do_indent);
@@ -670,7 +667,6 @@ int main(int argc, char *argv[]) {
                 if (fh) {
                     std::fputws(output_wtext.c_str(), fh);
                     fclose(fh);
-                exit(0);
                 } else {
                     std::fwprintf(stderr, _(L"Opening \"%s\" failed: %s\n"), output_location,
                                   std::strerror(errno));
@@ -693,5 +689,7 @@ int main(int argc, char *argv[]) {
             }
 
             std::fputws(str2wcstring(colored_output).c_str(), stdout);
-    return ret;
+        }
+    }
+    return 0;
 }