(1)
do-something;
if (success) {
do-this;do-that;...[many lines of stuff]do-some-other-thing;
}
else
{
print-error-message-and-exit;
}
(2)
do-something;
if (failure) {
print-error-message-and-exit;
}
do-this;
do-that;
...
[many lines of stuff]
do-some-other-thing;
I could go on at length to try to justify my strong preference, but I won't. In the end, it's just taste.
No, I take it back, I will rationalize a little. Here are some reasons I prefer #2.
- It's shorter overall.
- The short alternative comes first, so you don't overlook it in the noise.
- There's one fewer nesting level to puzzle through. This also occasionally permits longer lines without word-wrap.
- It feels more like exception handling, and saying what I mean: A problem? Let's bail.
In Perl, the solution is even more stereotyped and easy-to-read:
do-something OR die "it didn't work";...
In bash, I use a shell function, die(), which I wrote to let me code in the same style:
do-something || die "It didn't work"
...
