Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

What I'm looking for is something that would perform a series of commands like this:

# cat file1 >> concated_file
# cat file2 >> concated_file
# cat file3 >> concated_file
# cat file4 >> concated_file

But wouldn't require me to retype the whole command 3 additional times. Maybe just be able to replace the argument from the previous command with syntax like the following:

# cat file1 >> concated_file
# s/file1/file2
# s/file2/file3
# s/file3/file4

I know that if the last argument is the same you could do this:

# cp -p test1.txt test2.txt
# chmod 777 $_
# chown nimmylebby: $_

And you could also use Bash loops like so:

# for f in 'file1' 'file2'; 
> do 
> chmod 750 $f;
> done

However, the above 2 examples are not what I'm looking. I just want to perform a series of commands which only differ by one argument without using for loops. Is this possible? Might not be but hoping it is ;-).

share|improve this question
1  
at least for me it is not clear of what you want to do ... –  akira Oct 17 '10 at 14:11
    
Heh guess it's you + atleast another person. I'll try to add more clarification in the last "looking for" example. –  Belmin Fernandez Oct 17 '10 at 14:30
add comment

2 Answers

up vote 3 down vote accepted
  • Press Up, edit the command as necessary, press Enter.

  • As previously, but arrange for the changing word to come last in the command for easier edition, e.g., cat >> concated_file file1. This is straightforward with your example command, not so in all cases.

  • Define a function taking the variable part as an argument: f () { cat "$1" >> concated_file; }. Then invoke the function several times: f file1, f file2, …

  • Use history expansion. Here you can do ^file1^file2.

share|improve this answer
    
Left the best for last huh? History expansion is exactly what I was looking for. Thanks!! –  Belmin Fernandez Oct 17 '10 at 15:05
    
History expansion is awesome, +1 for you. –  Wuffers Oct 17 '10 at 15:11
add comment

Maybe what you need is a function:

function mycat() { cat $1 >> concated_file; }
mycat file1
mycat file2
mycat file3
mycat file4
share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.