Monday, May 18, 2009

Linux tip: history and !

Ever find yourself trying to remember a series of steps you recently did in Linux? Try typing the command "history" at the command line (without the quotes). You'll see a long list of your most recently used commands. It looks like this:

1018 ls
1019 cd

1020 cd /scratch/turnersd/

1021 ls

1022 cd

1023 grep -P "\s(10|9|8)\s" /scratch/turnersd/alz/parsed.txt | awk '{print $1"\n"$2}' | sort | uniq | perl -pi -e 's/RS/rs/g'

1024 history

Which brings me to my second tip, ! commands. Notice that when you type history the commands are numbered. 1023 in particular was a long string of commands I wouldn't want to retype over and over. Fortunately Linux lets me repeat that command any time I want just by typing an exclamation point followed by the number, like this — !1023 — at the command line, which does the same thing as typing it in the long way.

1 comment:

  1. cool tip!
    CTRL-r lets you type in parts of a command and searches the history.


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Getting Genetics Done by Stephen Turner is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.