Ask HN: What are your top most useful Unix commands?

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	Ask HN: What are your top most useful Unix commands?
	7 points by nns 2427 days ago

14 comments

DrScump 2426 days ago

kill lets you send any signal to a process you have control over. Corresponding signal handlers allow a wide range of behavior changes.

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ksaj 2425 days ago

A lot of people only know about its use for literally killing a process. But as an example of where I find myself using it fairly often is:

kill -USR1 <dd>

where <dd> is the process ID (obtained from ps) for the dd command.

Instead of killing dd, it reports back how much has been read/copied so far. Especially useful for working with large files and you decide you want to guestimate how much longer the copy will take.

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simonblack 2426 days ago

ls, find, grep, tar, cpio

But in truth, it's the bash scripting 'glue' that holds everything together.

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kleer001 2426 days ago

the semicolon ";" for chaining commands

ls -l

the "alias" command in a file for setting up quick-commands

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antoineMoPa 2426 days ago

grep, find, tail -f (useful to look at log files as they update)

Extras: sort, uniq, sed, sftp, apropos, man

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jjjbokma 2426 days ago

tail -F

This will also follow a log file if it rotates.

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jolmg 2426 days ago

I just found out a few days ago that `-F` works with multiple files, too. When there's new content on one, tail prefixes the output with a header, telling you what file it is.

I've used that to watch all logs apache and descendant processes could be writing to:

  pstree -p $(pgrep -o apache2) \
  | grep -Po '[^}]\(\K\d+'
  | sed ':b;N;$!bb;s/\n/,/g' \
  | sudo xargs lsof -d 0-1000 -a -p \
  | grep -Po '\S+$' \
  | grep 'log' \
  | sort -u \
  | xargs tail -F

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apotatopot 2427 days ago

top

jk, but also not.

w !sudo tee % in vim, even tho that's not really directly a unix thing?

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potta_coffee 2426 days ago

history | grep <command halfway remember using>

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0x445442 2427 days ago

dirs -v pushd popd

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