Tool to find GIT stashes containing changes to specified file(s)

stashd.d

#!/usr/bin/env rdmd
// Get rdmd from https://dlang.org/download.html (or brew, nix, apt, yum)
// Copyright Lionello Lunesu. Placed in the public Domain.
// https://gist.github.com/lionello/84cad70f835131198fee4ab7e7592fce

import std.stdio : writeln;

int main(string[] args) {
  import std.process : pipeProcess, wait, Redirect;

  if (args.length < 2) {
    return usage(args[0]);
  }

  // FIXME: support proper command line arguments
  const filenames = args[1..$];
  auto extraArgs = detectTerminal() ? ["--color=always"] : [];
  foreach (arg; filenames) {
    if (arg == "--") break;
    if (arg == "-h" || arg == "--help") return usage(args[0]);
    if (arg.length >= 2 && arg[0] == '-') extraArgs ~= arg;
  }

  auto pipes = pipeProcess(["git", "stash", "list", "-p"] ~ extraArgs, Redirect.stdout);

  enum STASH = "stash@{";
  enum DIFF = "diff --git a/";

  string lastStash = null;
  bool dump = false;
  foreach (line; pipes.stdout.byLine) {
    if (line.length > 10) {
      // Find the start of the filenames by skipping ANSI color and the diff prefix
      const start = line[0] == '\x1b' ? 4 : 0;
      const end = start + DIFF.length;
      if (line.length > end && line[start..end] == DIFF) {
        // Encountered a new diff; stop dumping and check filenames
        dump = false;
        if (anyMatch(filenames, line[end..$])) {
          // Found a match; print stash header if not yet printed
          if (lastStash) {
            writeln(lastStash);
            writeln();
            lastStash = null;
          }
          dump = true;
        }
      } else if (line[0..7] == STASH) {
        // Encountered a new stash; stop dumping but save header in case a file matches
        dump = false;
        lastStash = line.idup;
      }
    }
    if (dump) {
      writeln(line);
    }
  }
  return wait(pipes.pid);
}

@nogc @safe pure nothrow
private bool anyMatch(in char[][] names, in char[] line) {
  import std.string : indexOf;
  foreach (name; names) {
    if (line.indexOf(name) >= 0) {
      return true;
    }
  }
  return false;
}

private int usage(string arg0) {
  import std.path : baseName;
  writeln("Usage: ", arg0.baseName, " [<diff options>] [--] filename...");
  return 129;
}

// Inspired by DMD's src/dmd/console.d
private bool detectTerminal() {
  import std.process : environment;
  import core.sys.posix.unistd : isatty, STDOUT_FILENO;
  const term = environment.get("TERM");
  return isatty(STDOUT_FILENO) && term && term != "dumb";
}

You can use nix-shell -p ldc dtools to get the #dlang tools rdmd and ldc, or nix-shell -p ldc --run "ldc2 stashd.d" to build the executable. More options at https://dlang.org/download.html

Updated to use indexOf for matching parts of paths and using detectTerminal to decide whether or not to print ANSI color codes.

Now passing command line options to git stash list and handling -h and --help.