pid=`cat $pidfile` or read pid <$pidfile?

Question

I read a lot of init.d scripts and:

pid=`cat $pidfile`

lines make me sad. I don\'t understand why people doesn\'t use:

<         


        

Answer 1

The read pid < file way is the Best Practice for the reason you stated: much cheaper than a fork/exec of cat.

As for why so many scripts do this the expensive way, I can only speculate. Probably cut'n'paste from other people's scripts, together with lack of knowledge of shell features, together with blazingly fast CPUs. Who reads man pages when there's Stack Overflow? :-) Especially the shell man page is a hard-to-read reference manual for novices due to all the terminology introduced.

Who said Useless Use of Cat was a privilege for pipes?