All with only one pipe. Should be much faster as well (sort is slow). Use find instead of ls for recursion or reliability. Edit: case insensitive Show Sample Output

This command allows you to stream your log files, including gziped files, into one stream which can be piped to awk or some other command for analysis. Note: if your version of 'find' supports it, use: find /var/log/apache2 -name 'access.log*gz' -exec zcat {} + -or -name 'access.log*' -exec cat {} +

You can also do this for seconds, minutes, hours, etc... Can't use dates before the epoch, though. Show Sample Output

Much simpler method. More portable version: ssh host -l user "`cat cmd.txt`"

I was tired of the endless quoting, unquoting, re-quoting, and escaping characters that left me with working, but barely comprehensible shell one-liners. It can be really frustrating, especially if the local and remote shells differ and have their own escaping and quoting rules. I decided to try a different approach and ended up with this.

Problem: you want to output one line per file. you can't just 'tr -d' because you want one line per file and you don't want to use a loop. Solution: use awk to print each line without the record separator and a newline after each file. Show Sample Output

You have a python script that slowly prints output, you want to pipe the output to grep or tee, and you are impatient and want to watch the results right away. Rather than modify your script (making it slightly less efficient), use the -u option to have the output unbuffered.

If you want to be notified when a long-running command is finished, but you have already started it: CTRL+Z fg; echo "finished" | sendmail me@example.com I use a script to post a tweet, which sends me a txt: fg; echo "finished" | tweet

Rebuild flv files that are broken (can't seek). This method probably works for other video/audio formats that can become broken in the same way.

It just colorizes the line based on if it has 0, 1 or 2 tabs at the beginning of the line. Won't work so well if lines already begin with tabs (too bad comm doesn't have an option to substitute \t for something else). Don't forget comm needs input files to be sorted. You can use a shortcut like this with bash: comm Show Sample Output

The options -b binary and -m are needed for disassembling raw machine code when it is not part of a full binary executable with proper headers. Show Sample Output

preferred way to query ps for a specific process name (not supported with all flavors of ps, but will work on just about any linux afaik) Show Sample Output

Good for fixing web permissions. You might also want to do something like this and skip files or directories that begin with a period: find public_html/stuff -not -name ".*" \( -type d -exec chmod 755 {} + -o -type f -exec chmod 644 {} + \) ...or include a special case for scripts: find public_html/stuff -type d -exec chmod 755 {} + -or -type f -name "*.pl" -exec chmod 755 {} + -or -exec chmod 644 {} +

time perl -e 'if(opendir D,"."){@a=readdir D;print $#a - 1,"\n"}' 205413 real 0m0.497s user 0m0.220s sys 0m0.268s time { ls |wc -l; } 205413 real 0m3.776s user 0m3.340s sys 0m0.424s ********* ** EDIT: turns out this perl liner is mostly masturbation. this is slightly faster: find . -maxdepth 1 | wc -l sh-3.2$ time { find . -maxdepth 1|wc -l; } 205414 real 0m0.456s user 0m0.116s sys 0m0.328s ** EDIT: now a slightly faster perl version perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' sh-3.2$ time perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' 205414 real 0m0.415s user 0m0.176s sys 0m0.232s

Limited, but useful construct to extract text embedded in XML tags. This will only work if bar is all on one line. If nobody posts an alternative for the multiline sed version, I'll figure it out later...

If you use 'tail -f foo.txt' and it becomes temporarily moved/deleted (ie: log rolls over) then tail will not pick up on the new foo.txt and simply waits with no output. 'tail -F' allows you to follow the file by it's name, rather than a descriptor. If foo.txt disappears, tail will wait until the filename appears again and then continues tailing.

Add this to your $HOME/.bashrc file. It will only set this prompt if it is running inside screen ($WINDOW var is set) Looks like this... ion@atomos:~[2]$ Show Sample Output

Breaks down and numbers each line and it's fields. This is really useful when you are going to parse something with awk but aren't sure exactly where to start. Show Sample Output

Directly attach a remote screen session (saves a useless parent bash process)

command to decrypt: openssl enc -aes-256-cbc -d < secret.tar.enc | tar x Of course, don't forget to rm the original files ;) You may also want to look at the openssl docs for more options.