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Commands by alvinx

Terminal - Commands by alvinx - 12 results

grep . filename > newfilename

2009-09-25 09:25:34

User: alvinx

Functions: grep

Up
Down

Remove blank lines from a file using grep and save output to new file

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$ awk '{printf "select * from table where id = %c%s%c;\n",39,$1,39; }' inputfile.txt

2009-09-21 14:08:04

User: alvinx

Functions: awk

Up
Down

create SQL-statements from textfile with awk

inputfile.txt is a space-separated textfile, 1st column contains the items (id) I want to put into my SQL statement.

39 = charactercode for single tick '

1 = first column

If inputfile.txt is a CSV-file separated by "," use FS= to define your own field-separator:

awk 'BEGIN {FS=","; }{printf "select * from table where id = %c%s%c;\n",39,$1,39; }' inputfile.txt

apt-get install sl; sl

2009-09-21 13:55:24

User: alvinx

Functions: apt install

Up
Down

Learn how to stop mistyping "ls" the fun way

this is funny ;)

alias sl="ls" ... is the useful solution, but that's boring ;P and You won't learn to think before You type !

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sudo find /var/log/ -mtime -7 -type f | xargs du -ch | tail -n1

2009-08-27 14:18:47

User: alvinx

Functions: du find sudo tail xargs

Up
Down

get diskusage of files modified during the last n days

get diskusage of files (in this case logfiles in /var/log) modified during the last n days:

sudo find /var/log/ -mtime -n -type f | xargs du -ch

n -> last modified n*24 hours ago

Numeric arguments can be specified as

+n for greater than n,

-n for less than n,

n for exactly n.

=> so 7*24 hours (about 7 days) is -7

sudo find /var/log/ -mtime -7 -type f | xargs du -ch | tail -n1

echo 1234567890 | awk '{ print strftime("%c", $0); }'

2009-08-25 09:37:54

User: alvinx

Functions: awk echo

Up
Down

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; }

rsync --partial --progress --rsh=ssh user@host:remote-file local-file

2009-08-25 09:32:07

User: alvinx

Functions: rsync

Up
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resume scp-filetransfer with rsync

resume a partial scp-filetransfer with rsync

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bash-hotkey: <CTRL+x+e>

2009-08-25 09:08:54

User: alvinx

Functions: bash

Up
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bash: hotkey to put current commandline to text-editor

* in bash-shell You can capture the current commandline to a text-editor:

* simply press: CTRL+x+e

* Your current commandline will pe put into Your default text-editor (export EDITOR=vim)

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ps aux | grep [c]ommandname

2009-08-17 12:29:16

User: alvinx

Functions: grep ps

-4

Up
Down

omit grep

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SELECT relname, reltuples, pg_relation_size(relname) FROM pg_class r JOIN pg_namespace n ON (relnamespace = n.oid) WHERE relkind = 'r' AND n.nspname = 'public' ORDER BY relname;

2009-08-17 11:46:34

User: alvinx

Up
Down

postgresql SQL to show count of ALL tables (relations) including relation-size

Postgresql specific SQL

- to show count of ALL tables including relation-size (pg_relation_size = used space on filesystem)

- might need a VACUUM ANALYZE before showing all counts correctly !

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$ vim ... :help 42

2009-08-17 11:37:02

User: alvinx

Functions: vim

Up
Down

vim easter egg

inside vim try:

:help 42

to get the meaning of life, the universe and everything !

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watch "ps auxw | grep [d]efunct"

2009-08-12 08:11:16

User: alvinx

Functions: watch

Tags: grep watch ps defunct

Up
Down

Get a regular updated list of zombies

to omit "grep -v", put some brackets around a single character

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man -P cat ls > man_ls.txt

2009-07-27 13:09:24

User: alvinx

Functions: cat ls man

Up
Down

save a manpage to plaintext file

Output manpage as plaintext using cat as pager: man -P cat commandname

And redirect its stdout into a file: man -P cat commandname > textfile.txt

Example: man -P cat ls > man_ls.txt

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