Command (Linux): use /bin/sh as the default shell

src/data/help.txt

@@ -144,7 +144,7 @@ Module specific options:
     --weather-output-format:                 The output weather format to be used. It must be URI encoded.
     --player-name:                           The name of the player to use
     --opengl-library <value>:                Set the OpenGL context creation library to use. Must be auto, egl, glx or osmesa. Default is auto
-    --command-shell <str>:                   Set the shell program to execute the command text. Default is cmd for Windows, csh for FreeBSD, bash for others
+    --command-shell <str>:                   Set the shell program to execute the command text. Default is cmd for Windows, /bin/sh for *nix
     --command-key <str>:                     Set the module key to display
     --command-text <str>:                    Set the command text to be executed
     --colors-symbol <str>:                   Set the symbol to be printed by Colors module. Default is block

src/modules/command/command.c

@@ -39,13 +39,11 @@ void ffInitCommandOptions(FFCommandOptions* options)
     options->moduleName = FF_COMMAND_MODULE_NAME;
     ffOptionInitModuleArg(&options->moduleArgs);
 
-    ffStrbufInitS(&options->shell,
+    ffStrbufInitStatic(&options->shell,
         #ifdef _WIN32
-        "cmd"
-        #elif defined(__FreeBSD__)
-        "csh"
+        "cmd.exe"
         #else
-        "bash"
+        "/bin/sh"
         #endif
     );