Avoiding wildcard expansion in Bash loop

Question

I want to use a list as parameter to a for-loop; but with double quotes, the list isn't understood as a list, and without quotes, the wildcards are evaluated to filenames.

A="a* b*"

for ex in "$A"; do
    echo "$ex";
done

for ex in $A; do
    echo "$ex";
done

The first one prints:

a* b*

The latter prints:

a.txt
b.txt

I want:

a*
b*

How can I make this work?

errr... I think I am becoming blind... what is the difference between the two loops? — thkala, Nov 07 '12 at 13:36
thkala, agreed. Presumably one of them should NOT have $A surrounded with dbl-quotes. Good luck to all. — shellter, Nov 07 '12 at 14:23

score 5 · Accepted Answer · answered Nov 07 '12 at 13:41

5

You can set -f to disable pathname expansion:

A="a* b*"

( set -f
  for ex in $A ; do
      echo "$ex"
  done
)

answered Nov 07 '12 at 13:41

choroba

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chepner · Answer 2 · 2012-11-07T20:50:47.980

4

Use an array:

A=("a*" "b*")
for ex in "${A[@]}"; do
    echo "$ex"
done

edited Nov 07 '12 at 20:50

answered Nov 07 '12 at 13:46

chepner

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610

Typo: `for x` should be `for ex` – Hai Vu Nov 07 '12 at 16:09

Avoiding wildcard expansion in Bash loop

2 Answers2