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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
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All commands from sorted by
Terminal - All commands - 12,387 results
mysql -u <user> --password=<password> -e "SHOW COLUMNS FROM <table>" <database> | awk '{print $1}' | tr "\n" "," | sed 's/,$//g'
2009-10-29 13:42:17
User: maxmanders
Functions: awk sed tr
-1

Useful when you need to write e.g. an INSERT for a table with a large number of columns. This command will retrieve the column names and comma-separate them ready for INSERT INTO(...), removing the last comma.

ps -eo user,pcpu,pmem | tail -n +2 | awk '{num[$1]++; cpu[$1] += $2; mem[$1] += $3} END{printf("NPROC\tUSER\tCPU\tMEM\n"); for (user in cpu) printf("%d\t%s\t%.2f\t%.2f\n",num[user], user, cpu[user], mem[user]) }'
2009-10-29 12:49:01
User: georgz
Functions: awk ps tail
7

The original version gives an error, here is the correct output

(crontab -e) 00 12 * * * apt-get update (/etc/init.d/cron restart)
find . -name '*.java' | xargs -L 1 cpp -fpreprocessed | grep . | wc -l
2009-10-29 09:58:43
User: rbossy
Functions: cpp find grep wc xargs
2

I took java to make the find command simpler and to state that it works for any language supported by cpp.

cpp is the C/C++ preprocessor (interprets macros, removes comments, inserts includes, resolves trigraphs). The -fpreprocessor option tells cpp to assume the input has already been preprocessed so it will only replace comment lines with blank lines.

The -L 1 option tells xargs to launch one process for each line, indeed cpp can only process one file at the time...

mysqldump -uUSERNAME -pPASSWORD database | gzip > /path/to/db/files/db-backup-`date +%Y-%m-%d`.sql.gz ;find /path/to/db/files/* -mtime +5 -exec rm {} \;
gcc -dM -E - <<<''
gcc -dM -E - < /dev/null
TIMEUNIT=$(awk '/timescale/{print NR}' a)
TIMEUNIT=$( cat a | grep -n "timescale" | awk -F ":" '{ print $1 } ' )
ls -1rSA | tail
2009-10-27 15:34:59
User: rbossy
Functions: ls
-5

This will only work on files since ls won't tell the size of a directory contents.

Note that the first switch is the digit one, not the letter ell.

watch -n 60 du /var/log/messages
alias clear='( for ((i=1;i<$LINES;i++)) ; do echo "" ; done ) ; clear'
2009-10-27 14:38:31
User: Marcio
Functions: alias echo
-3

If you receives a lot of compiling errors, type 'clear', then reedit your code and press "SHIFT+PGUP".

export PROMPT_COMMAND='( x=$? ; let x!=0 && echo shell returned $x )'
STAT=`curl http://www.whatismyip.org/`; curl -u YourUserName:YourPassword -d status=$STAT http://twitter.com/statuses/update.xml
2009-10-26 23:02:30
User: m33600
-1

Easy way to find your computers IP in one place, ie, twitter

It suppress the need of dyndns clients and remembering the complex names they give you.

I put it inside KAlarm ( the cron GUI for KDE, ubuntu), to update my ip every 3 minutes.

I did not add the cron statements to keep the code clean.

shopt -s cdable_vars
2009-10-26 22:10:56
User: haivu
Tags: bash shell
4

Usage:

mydir=/very/long/path/to/a/dir cd mydir

I often need to cd where no man wants to go (i.e. long path). by enabling the shell option cdable_vars, I can tell cd to assume the destination is the name of a variable.

dpigs
awk 'BEGIN {for(i=1;i<=100;i++)sum+=i}; END {print sum}' /dev/null
2009-10-26 18:24:57
User: dennisw
Functions: awk
Tags: awk
0

Calculating series with awk only, no need for seq: add numbers from 1 to 100

Variations:

1+3+...+(2n-1) = n^2

awk 'BEGIN {for(i=1;i<=19;i+=2)sum+=i}; END {print sum}' /dev/null # displays 100

1/2 + 1/4 + ... = 1

awk 'BEGIN {for(i=1;i<=10;i++)sum+=1/(2**i)}; END {print sum}' /dev/null # displays 0.999023
ssh-keygen -l -f /etc/ssh/ssh_host_rsa_key.pub && ssh-keygen -l -f /etc/ssh/ssh_host_dsa_key.pub
2009-10-26 17:52:41
Functions: ssh ssh-keygen
Tags: ssh bash
4

Get your server's fingerprints to give to users to verify when they ssh in. Publickey locations may vary by distro. Fingerprints should be provided out-of-band.

curl http://www.whatismyip.org/
flip -u $FILE
2009-10-26 17:33:26
Tags: flip
0

conversely, you can type

flip -m

to convert the file back to MS line endings.

tr -d '\r\n' < input_file.txt > output_file.txt
2009-10-26 16:12:21
User: nadavkav
Functions: tr
3

Remove CR LF (CRLF) from a text file. use man:tr to get more info about removing other characters from a file. and even character to character replacements.

curl -s checkip.dyndns.org | grep -Eo '[0-9\.]+'
getdji (){local url sedcmd;url='http://finance.yahoo.com/q?d=t&s=^DJI';sedcmd='/(DJI:.*)/,/Day.*/!d;s/^ *//g;';sedcmd="$sedcmd/Change:/s/Down / -/;/Change:/s/Up / +/;";sedcmd="$sedcmd/Open:/s//& /";lynx -dump "$url" | sed "$sedcmd"; }
w3m http://amit-agarwal.co.in/mystuff/getip_txt.php will return the ip in text format.
w3m miip.cl | grep ip
2009-10-26 01:40:37
User: Cont3mpo
Functions: grep
-2

See external ip with w3m, simple and fast.

On a web site from Chile (spanish).