My first shell script ever

CGameProgrammer · 03-09-2005, 03:05 AM

Just wrote my first shell script, though it seems sort of sloppy to me. I wanted to rename 40-50 .html files to .txt, so I read a shell-scripting tutorial, learned a few new Linux commands, and eventually wrote this:

Code:

for F in `ls -a1 *.html`
    do
    wc=`echo -n $F | wc -m`
    len=`expr $wc - 5`
    p="%.`echo $len`s.txt\n"
    name=`printf $p $F`
    mv $F $name
    done

But because you can't nest backquotes, I used a bunch of those temporary variables (which I think looks sloppy) and when setting "p" you'll notice I used backquotes with an echo command, because it couldn't parse "%.$lens.txt\n". But that's an ugly hack IMO.

So, can someone suggest a better way of doing this sort of script?

trevelluk · 03-09-2005, 03:44 AM

I think this should work.

Code:

#!/bin/bash

for F in `ls -a1 *.html`
    do
    mv $F `basename $F .html`.txt
done

baltho · 03-09-2005, 03:45 AM

Hi there!!

In my experience, there's always at least a dozen ways to do the same thing in a shell script, so this is just what I'd do, but here goes...

for from in `ls *.html`
do
to=`echo $from | sed -e "s/.html\$/.txt/"`
mv $from $to
done

I find sed quite fiddly to work with, but VERY useful - tweaking the sed command and "echo"ing the mv command until I get it right is how I do it.

Hope it helps......

CGameProgrammer · 03-09-2005, 09:35 AM

Ah, basename is a very easy way to do it -- wish I'd known about it.

Never heard of the sed command before, either; I'll have to look up how to use it.

frieza · 03-09-2005, 09:40 AM

3 usefull commands to learn... i'm still learning them

grep, sed, awk

CGameProgrammer · 03-09-2005, 11:25 AM

I use grep alot, but I've never used those other two.

tokiko · 03-11-2005, 04:43 PM

you don't even need a shell script; just use the "rename" command :P

rename .html .txt *

CGameProgrammer · 03-11-2005, 05:17 PM

Wow, lol. Linux has too many obscure commands.

AxeZ · 03-11-2005, 06:30 PM

There is no such thing as "too many"...