From ab952e58639a4e7c0596b4bedc16cd99adbe68a3 Mon Sep 17 00:00:00 2001
From: Samuel Dionne-Riel <samuel@dionne-riel.com>
Date: Tue, 24 Mar 2020 15:24:51 -0400
Subject: [PATCH] mirror: Introduce two functions for running commands

They are thin wrappers over `system`, but two main points:

 * They log the (unescaped) command.
 * `run` will auto-die.

This removes the need to pepper `== 0 or die` in the script.
---
 mirror-nixos-branch.pl | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/mirror-nixos-branch.pl b/mirror-nixos-branch.pl
index e9226c8..25ab9ec 100755
--- a/mirror-nixos-branch.pl
+++ b/mirror-nixos-branch.pl
@@ -15,6 +15,27 @@ use List::MoreUtils qw(uniq);
 use Net::Amazon::S3;
 use POSIX qw(strftime);
 
+# Runs the given command, printing the (unescaped) command.
+# This command continues on failure.
+sub runAllowFailure {
+    print STDERR " \$ ", join(" ", @_), "\n";
+    system(@_);
+}
+
+# Runs the given command, printing the (unescaped) command.
+# This command dies on failure.
+sub run {
+    my $context = caller(0);
+    my $code = runAllowFailure(@_);
+    unless ($code == 0) {
+        my $exit = $code >> 8;
+        my $errno = $code - ($exit << 8);
+        die "Command failed with code ($exit) errno ($errno).\n";
+    }
+
+    return $code;
+}
+
 my $channelName = $ARGV[0];
 my $releaseUrl = $ARGV[1];