Commands by hell9001 (1)

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Load another file in vim
You can then switch from a file to another with ^W^W

Wait for file to stop changing
Here's a way to wait for a file (a download, a logfile, etc) to stop changing, then do something. As written it will just return to the prompt, but you could add a "; echo DONE" or whatever at the end. This just compares the full output of "ls" every 10 seconds, and keeps going as long as that output has changed since the last interval. If the file is being appended to, the size will change, and if it's being modified without growing, the timestamp from the "--full-time" option will have changed. The output of just "ls -l" isn't sufficient since by default it doesn't show seconds, just minutes. Waiting for a file to stop changing is not a very elegant or reliable way to measure that some process is finished - if you know the process ID there are much better ways. This method will also give a false positive if the changes to the target file are delayed longer than the sleep interval for any reason (network timeouts, etc). But sometimes the process that is writing the file doesn't exit, rather it continues on doing something else, so this approach can be useful if you understand its limitations.

move you up one directory quickly
Alias a single character 'b' to move to parent directory. Put it into your .bashrc or .profile file. Using "cd .." is one of the most repetitive sequence of characters you'll in the command line. Bring it down to two keys 'b' and 'enter'. It stands for "back" Also useful to have multiple: alias b='cd ../' alias bb='cd ../../' alias bbb='cd ../../../' alias bbbb='cd ../../../../'

Retrieve a random command from the commandlinefu.com API
Seeing that we get back plain text anyway we don't need lynx. Also the sed-part removes the credit line.

list block devices
Shows all block devices in a tree with descruptions of what they are.

convert unixtime to human-readable with awk
- convert unixtime to human-readable with awk - useful to read logfiles with unix-timestamps, f.e. squid-log: sudo tail -f /var/log/squid3/access.log | awk '{ print strftime("%c ", $1) $0; }

Delete all empty lines from a file with vim
This command delete all the empty lines (include the lines with space) from a file. g = global command \S = non-whitespace character; !\S the opposite d = delete a range

direct a single stream of input (ls) to multiple readers (grep & wc) without using temporary files

Limit the cpu usage of a process
Similar to `cpulimit`, although `prlimit` can be found shipped with recent util-linux. Example: limit CPU consumption to 10% for a math problem which ordinarily takes up 100% CPU: Before: $ bc -l

mix video and audio
-map 0.0:0 map the video of video.mp4 to the video of mix.mp4 -map 1.0:1 map the audio of audio.mp3 to the audio of mix.mp4 make sure that video.mp4 and audio.mp3 have the same duration


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