I mean some command subtitutions. In the past I was able to use backticks in Bash, when for example I had to download a list of files / links which had been already collected in a text file, line by line:
wget `cat list.txt`
and even megadl to download from mega:
megadl `cat list.txt`
Unfortunately it doesn't work right now as expected for some reason. I get the whole file list as a long line of text separated by spaces instead of newlines.
I often write small scripts which can handle only one argument which is a file, but not a list of files, listed in a text file. Of course I don't want to modify my scripts, because Bash provide this helper mechanism, to apply the same command to a list of files, for example on the output of "ls -1 *.jpg". I have a small utility called "cgamma" which apply gamma correction to image files while preserving the colour saturation ( it simply calls imagemagick's mogrify). And I would like to use it on many image files, like this:
cgamma `ls -1 *.jpg` 1.3
I know I could use a for loop one-liner, but it is more typing:
for $i in $(ls -1 *.jpg);do cgamma $i 1.3;done
So my question is, how can I use properly the backticks, command substitution, to process file lists, and apply the same command to all of them?
You can use xargs:
printf '%s\0' *.jpg | xargs -0 -I {} cgamma '{}' 1.3