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

7 points by nns 6 years ago | 17 comments

DrScump 6 years ago |

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

ksaj 6 years 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.

simonblack 6 years ago |

ls, find, grep, tar, cpio

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

kleer001 6 years ago |

the semicolon ";" for chaining commands

ls -l

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

antoineMoPa 6 years ago |

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

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

jjjbokma 6 years ago | |

tail -F

This will also follow a log file if it rotates.

jolmg 6 years 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

apotatopot 6 years ago |

top

jk, but also not.

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

potta_coffee 6 years ago |

history | grep <command halfway remember using>

0x445442 6 years ago |

dirs -v pushd popd

wbsun 6 years ago |

cd pwd ls

runjake 6 years ago |

cut, awk, sed, comm, grep

jolmg 6 years ago |

git

sgillen 6 years ago |

emacs&

jjjbokma 6 years ago |

find, grep

hntddt1 6 years ago |

chmielewski 6 years ago |

time cat

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