Fastfetch: adds support for reading JSON config from stdin

Author: CarterLi

CHANGELOG.md

@@ -4,6 +4,7 @@ Changes:
 * Keys in JSON configuration files are now case-sensitive, as stated in v2.49.0
     * This is a breaking change, but it should not affect most users as long as your config file passes JSON schema validation.
 * All module config flags have been removed, as stated in v2.49.0
+    * To configure modules at command line, `echo '{"modules": [{"type":"custom","format":"Hello Fastfetch!"}]}' | fastfetch -c -` should be used instead.
 * Percent bar config `display.bar.*` options have been replaced with a more organized, nested object structure.
     * `display.bar.charElapsed` has been renamed to `display.bar.char.elapsed`.
     * `display.bar.charTotal` has been renamed to `display.bar.char.total`.
@@ -13,6 +14,7 @@ Changes:
     * `--config` or `-c` should be used instead.
 
 Features:
+* Added support for reading JSON config from stdin using `--config -` or `-c -`
 * Added `display.bar.border.{leftElapsed,rightElapsed}` for using border as parts of bar content. (#1875)
     * `display.bar.border: null` has been added as a shorthand to disable bar borders.
 * Added `display.bar.color.{elapsed,total,border}` to customize the color of the elapsed, total and border sections of the percent bar.

src/fastfetch.c

@@ -382,16 +382,25 @@ static bool parseJsoncFile(const char* path, bool strictJson)
 
     {
         yyjson_read_err error;
-        instance.state.configDoc = yyjson_read_file(path, strictJson ? 0 : YYJSON_READ_ALLOW_COMMENTS | YYJSON_READ_ALLOW_TRAILING_COMMAS, NULL, &error);
+        yyjson_read_flag flg = strictJson ? 0 : YYJSON_READ_ALLOW_COMMENTS | YYJSON_READ_ALLOW_TRAILING_COMMAS;
+        instance.state.configDoc = path
+            ? yyjson_read_file(path, flg, NULL, &error)
+            : yyjson_read_fp(stdin, flg, NULL, &error);
         if (!instance.state.configDoc)
         {
             if (error.code != YYJSON_READ_ERROR_FILE_OPEN)
             {
-                size_t row = 0, col = error.pos;
-                FF_STRBUF_AUTO_DESTROY content = ffStrbufCreate();
-                if (ffAppendFileBuffer(path, &content))
-                    yyjson_locate_pos(content.chars, content.length, error.pos, &row, &col, NULL);
-                fprintf(stderr, "Error: failed to parse JSON config file `%s` at (%zu, %zu): %s\n", path, row, col, error.msg);
+                if (path)
+                {
+                    size_t row = 0, col = error.pos;
+                    FF_STRBUF_AUTO_DESTROY content = ffStrbufCreate();
+                    if (ffAppendFileBuffer(path, &content))
+                        yyjson_locate_pos(content.chars, content.length, error.pos, &row, &col, NULL);
+                    fprintf(stderr, "Error: failed to parse JSON config file `%s` at (%zu, %zu): %s\n", path, row, col, error.msg);
+                }
+                else
+                    fprintf(stderr, "Error: failed to parse JSON from stdin at %zu: %s\n", error.pos, error.msg);
+
                 exit(477);
             }
             return false;
@@ -461,6 +470,12 @@ static void optionParseConfigFile(FFdata* data, const char* key, const char* val
     if (value[0] == '\0' || ffStrEqualsIgnCase(value, "none"))
         return;
 
+    if (value[0] == '-' && value[1] == '\0')
+    {
+        parseJsoncFile(NULL, false);
+        return;
+    }
+
     //Try to load as an absolute path
 
     FF_STRBUF_AUTO_DESTROY absolutePath = ffStrbufCreateS(value);