Maintain # of Digits in Bash Script

[jmadero]

Hi All,

I'm trying to maintain number of digits for a looped bash script I'm writing. Basically I have folders that are 4 digits long from 1 - 2500 so it's 0001, 0002, etc...

What I need is a way to check to see if /home/user/picture/0001 exists and then loop it all the way up to 2500. I have the loop down fine but it's chceking for /home/user/picture/1 instead of 0001. Thanks in advance

[histrungalot]

Use printf

#!/bin/bash

for i in {1..2500}
do
   st=`printf "%04d" $i`;
   echo $st
done

[BrianMicek]

histrungalot, I've never seen that bash notation used before "for i in {1..2500}"! Thanks

[Mudgen]

Nifty solution. printf didn't occur to me.

[Stooofer]

seq has a nice padding function

for i in `seq -w 1 2500`; do echo $i ; done

[jmadero]

Thanks for the replies, I did something slightly different (probably less efficient but it's such a small program it works fine), still need one more line of help. In my if statement I have this

if [ -d "/media/drive/$x ]; then
     cd /media/drive/$x
     mogrify -resize 1200 *.JPG
    x=$(( $x + 1))
fi

what I need is another check to find file size or dimension. I have manually changed the size of some of my pictures already and I want to skip those that have already been done (so anything smaller than 2 megs I would want to leave alone)

Thanks in advance

[histrungalot]

You can try stat

$ ls -l a.out
rwxrwxr-x. 1 guest guest 6568 Feb  6 06:10 a.out
$ stat -c %s a.out
6568
$

stat - Linux Command - Unix Command

[jmadero]

I don't think stat will work as there are a lot of pictures in each folder and there is no naming convention.

[Stooofer]

find will do the job for you
find -name \*.JPG -size 2M -exec mogrify -resize 1200 '{}' \;

this would pick out the JPG-files and the ones larger than 2 Mb will be mogrified

[histrungalot]

Try

#!/bin/bash
cd ./temp
FILES=$(ls *.JPG)
for i in $FILES
do
  num=$(stat -c %s $i)
  if [ "$num" -gt "2097152" ]
  then
    echo "do what you want with file: $i"
  fi
done