Using exec to jump

| 1 min read

In Mr Rob's dotfiles repo (see A new learning source for shell scripting) there's a treasure trove of content that is very pleasant to peruse.

In one of his streams I saw him use ix and thereby discovered - a simple pastebin. He uses his ix script to share code and other content, either from the command line or from within Vim directly. It's only 14 lines including comments, but I've learned stuff from it already.

If ix is invoked with an argument, it's treated as the unique identifier for a specific pastebin, and that pastebin is retrieved, such as 2pgP (which is another of his scripts with lots to learn from - twitch).

The part of ix that handles this is simply:

if [ -n "$1" ]; then
exec curl -s "$1"

Basically in this mode, there's no point in processing the rest of the script (beyond the small section you see here), so the handling of the input should finish when the pastebin is retrieved.

Until now, I would have written it like this:

if [ -n "$1" ]; then
curl -s "$1"

But that's simply unnecessary, and in fact arguably less efficient too. The Bash man page mentions, for exec, this fact: "If command is specified, it replaces the shell. No new process is created.". In other words, in this if ... fi, the curl command replaces the script's execution, rather than being executed as a sub process.

Sometimes there's a beauty in the smallest things.