Differences between revisions 9 and 12 (spanning 3 versions)
⇤ ← Revision 9 as of 2010-07-30 14:32:06 →
Size: 1429
Editor: GreyCat
Comment: fixes. fixes are good.
← Revision 12 as of 2015-03-05 00:30:34 → ⇥
Size: 1437
Editor: izabera
Comment: syntax hl
Deletions are marked like this. Additions are marked like this.
Line 5: Line 5:
{{{
    zcat -- *.gz		 {{{#!highlight bash
zcat -- *.gz
Line 15: Line 15:
{{{
    # Bourne
    for file in ./*.gz
    do
     echo "$file"
     # do something with "$file"
    done		 {{{#!highlight bash
# Bourne
for file in ./*.gz
do
    echo "$file"
    # do something with "$file"
done
Line 26: Line 26:
{{{
    # Bourne
    find . -name '*.gz' -type f -exec do-something {} \;		 {{{#!highlight bash
# Bourne
find . -name '*.gz' -type f -exec do-something {} \;
Line 33: Line 33:
{{{
    # Bash
    while IFS= read -r file; do
        echo "Now processing $file"
     # do something fancy with "$file"
    done < <(find . -name '*.gz' -print)		 {{{#!highlight bash
# Bash
while IFS= read -r file; do
    echo "Now processing $file"
    # do something fancy with "$file"
done < <(find . -name '*.gz' -print)

How can I run a command on all files with the extension .gz?

Often a command already accepts several files as arguments, e.g. 

   1 zcat -- *.gz

On some systems, you would use gzcat instead of zcat. If neither is available, or if you don't care to play guessing games, just use gzip -dc instead.

The -- prevents a filename beginning with a hyphen from causing unexpected results.

If an explicit loop is desired, or if your command does not accept multiple filename arguments in one invocation, the for loop can be used: 

   1 # Bourne
   2 for file in ./*.gz
   3 do
   4     echo "$file"
   5     # do something with "$file"
   6 done

To do it recursively, use find: 

   1 # Bourne
   2 find . -name '*.gz' -type f -exec do-something {} \;

If you need to process the files inside your shell for some reason, then read the find results in a loop: 

   1 # Bash
   2 while IFS= read -r file; do
   3     echo "Now processing $file"
   4     # do something fancy with "$file"
   5 done < <(find . -name '*.gz' -print)

This example uses ProcessSubstitution (see also FAQ #24), although a pipe may also be suitable in many cases. However, it does not correctly handle filenames that contain newlines. To handle arbitrary filenames, see FAQ #20.

CategoryShell

BashFAQ/015 (last edited 2015-03-05 00:30:34 by izabera)