How to Convert 5 to 005 or 36 to 036 in bash

[3rag0n]

The title says it all, please help - I need it to make my comic donwloader script :)

[dwhitney67]

I've used something like this when renaming JPG files; there's probably a niftier way. Hopefully someone will weigh in with something better.


#!/bin/sh

FILES=`find . -name '*.jpg'`

declare -i i
i=1

for file in $FILES
do
if [ "$i" -lt "10" ]
then
index="00$i"
elif [ "$i" -lt "100" ]
then
index="0$i"
else
index="$i"
fi

mv $file image$index.jpg

i=$i+1
done

[Bachstelze]

Just use printf. ;)


$ a=3; b=`printf "%03d" $a`; echo $b;
003

[3rag0n]

@dwhitney67 : Thanks, but your script turns 36 to 0036 instead of 036. Although in your code, I'd like to suggest that you use the rename command, it renames specific patterns in files.

@Bachstelze: Thanks!!! This works great.

[Arndt]

Just use printf. ;)


$ a=3; b=`printf "%03d" $a`; echo $b;
003

$ a=3; num=000$a; echo ${num:${#num}-3:3}
003

(From the man page, I thought ${num:-3:3} would work, but it doesn't.)

[falconindy]

$ a=3; num=000$a; echo ${num:${#num}-3:3}
003

(From the man page, I thought ${num:-3:3} would work, but it doesn't.)
It does work, but you need to wrap the -3 in parenthesis.

[~]$ a=3; num=000$a; echo ${num:(-3):3}
003

[apmcd47]

If it were ksh:

$ typeset -Z3 i
$ i=3
$ echo $i
003
$

But it's not. I'd go with the printf solution above.

Andrew