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.