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I have a list of files, with their full paths, one per line in a file "files.txt"

I was trying to move all of those files from their original location to a new directory.

I CDed into the directory where they live now and issued

for file in ~/Desktop/files.txt do mv $file ~/newfolder

but nothing happens. I am sure I am missing something obvious

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1  
You need some separators there, try to just echo it with: for file in ~/Desktop/files.txt; do echo $file; done. –  nerdwaller Jan 18 '13 at 17:01
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@nerdwaller that won't work, bash will just print "~/Desktop/files.txt" it won't read the file unless explicitly told to either by for n in $(cat files.txt); do something; done or while read n; do something; done < files.txt. –  terdon Jan 18 '13 at 17:24
    
@terdon, I wanted to edit it when I realized I was on non-thinking autopilot but it was past the expiration. Thanks for pointing it out and providing the fix :) –  nerdwaller Jan 18 '13 at 17:25

3 Answers 3

up vote 0 down vote accepted

bash won't read the contents of the file unless you tell it to.

for file in $(cat ~/Desktop/files.txt); do mv "$file" ~/newfolder; done
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If this is on a single line, you would need ; between $() and do. –  nerdwaller Jan 18 '13 at 17:20
    
thanks @nerdwaller - fixed –  Nifle Jan 18 '13 at 17:24
    
@nifle Would this work if the files all had different paths, when a path might be /Users/lombardi/work files/myfile.png and another in the same file.txt /docs/file.jpg? –  Steve Jan 18 '13 at 17:56
    
Useless use of cat, and your script breaks in multiple ways, even if a file just contains a space in its path. Please fix this, as this kind of a common cause for problems. –  slhck Jan 18 '13 at 18:06
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This still breaks on file names that contain spaces. Since IFS is set to any white space, a file name like Quarterly report.pdf will fail above, even though $file is quoted, since Bash will split loop arguments on the whitespace: first $file will contain "Quarterly" and on the next iteration it will contain "report.pdf". One workaround is to set IFS='\n', but a failsafe solution already exists in the < files.txt version. This is one of the reasons that it is not good to learn people to loop like this, since it will break sooner or later. –  Daniel Andersson Jan 18 '13 at 20:29

You need to tell your loop to read the file, otherwise it is just executing:

mv ~/Desktop/files.txt ~/newfolder

In addition, as nerdwaller said, you need separators. Try this:

while read file; do mv "$file" ~/newfolder; done < ~/Desktop/files.txt

If your paths or file names contain spaces or other strange characters, you may need to do this:

while IFS= read -r file; do mv "$file" ~/newfolder; done < ~/Desktop/files.txt

Notice the quotes " around the $file variable.

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Thanks for editing mine, I realized my error but was unable to correct (comment edit time limit) and was writing an answer when yours popped up. Thanks! –  nerdwaller Jan 18 '13 at 17:21
    
Thanks, that works too but I found the other post to be easier to remember for the future. –  Steve Jan 18 '13 at 17:47
    
No worries, they are both correct. –  terdon Jan 18 '13 at 17:50
    
I was going to make the same edit as you did, thanks :) (Sorry, it's just that there are so many "good enough" or mostly wrong Bash loops around on the Internet…) –  slhck Jan 18 '13 at 18:15
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Yeah, I just checked. With while, it works somewhat okay. It's just the -r option should be used to retain backslashes, and setting IFS= makes read not trim any leading or trailing whitespace. It's for that causes issues. See: Don't Read Lines With For –  slhck Jan 18 '13 at 18:29

If the filenames do not contain whitespace:

mv -t dest_dir $(< text.file)

is probably the most concise way.

If there is whitespace in the filenames

while IFS= read -r filename; do mv "$filename" dest_dir; done < test.file

is safe.

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