error when using wc -c with file names

Question

I am running this code, that sorts files in the desired folders. If a file name has 13 chars it should run the first statement, else the second.

for i in *.png; do if [ "$($i | wc -c)" -eq 13 ]; then
    echo cp $i $HOME/Desktop/final/pos_${i:0:1}/${i:0:3}.jpg
else
    echo cp $i $HOME/Desktop/final/pos_${i:0:1}/${i:0:4}.jpg
fi;
done

the problem is, that [ "$($i | wc -c)" -eq 13 ] is always 0, but clearly, file names have some length. What is the correct way of evaluating wc -c in an if statement?

use quotes in the `cp`. Maybe filename could contain spaces. :) — clt60, Apr 01 '17 at 10:23

score 3 · Accepted Answer · answered Apr 01 '17 at 10:07

3

Replace

[ "$($i | wc -c)" -eq 13 ]

by

[ $(printf "%s" "$i" | wc -c) -eq 13 ]

or use

[ ${#i} -eq 13 ]

answered Apr 01 '17 at 10:07

Cyrus

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where were you before... :P – sanjihan Apr 01 '17 at 10:18
for the full collection, also: `((${#i} == 13))` - arithmetic. :) – clt60 Apr 01 '17 at 10:19

Inian · Answer 2 · 2017-12-28T10:10:07.987

2

Use bash string utilities to get the string length. You don't need wc at all. And double-quote all variables in script to avoid word-splitting done by the shell.

for i in *.png; do 
    if ((${#i} == 13)); then
        echo cp "$i" $HOME/Desktop/final/pos_"${i:0:1}"/"${i:0:3}".jpg
    else
        echo cp "$i" $HOME/Desktop/final/pos_"${i:0:1}"/"${i:0:4}".jpg
    fi
done

edited Dec 28 '17 at 10:10

answered Apr 01 '17 at 10:10

Inian

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error when using wc -c with file names

2 Answers2