LinuxShort

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(Usefull short commands)
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* '''Print in fixed width format with awk'''
* '''Print in fixed width format with awk'''
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  echo $a $b $c |  awk '{for (i=1; i<=NF; i++) printf("%-20s ",$i);printf ("\n")}' > outfile.dat
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where strings a,b,c may be entire lines.

Revision as of 15:56, 14 December 2009

Usefull short commands

  • kill a process tree

When some script is started from a command line in a for-loop and a process tree is made, one should find the parent process and its PID and then simply kill it:

   $ pstree username -p 
   sshd(19953)---bash(19954)---bash(22238)---idl(22323)-+-{idl}(22326)
                                                        |-{idl}(22327)
                                                        |-{idl}(22328)
                                                        `-{idl}(22329) 
   sshd(20096)---bash(20097)
   sshd(20762)---bash(20763)
   sshd(21087)---bash(21088)-+-grep(21309)
                             `-top(21308)
   sshd(21736)---bash(21737)
   sshd(21780)---bash(21781)---pstree(22331)

Or if this tree is to long, one should grep the program (here:idl) with: $ pstree usrname -p | grep idl

   $ kill 19953  
   $ pstree username -p  
   sshd(20096)---bash(20097)
   sshd(20762)---bash(20763)
   sshd(21087)---bash(21088)-+-grep(21309)
                             `-top(21308)
   sshd(21736)---bash(21737)
   sshd(21780)---bash(21781)---pstree(22332)
  • Change sth inside file
  sed -i s/'\-9999'/'NaN'/g filename 

This will change -9999 with NaN inside a file, without making some tmp file in between.

  • Print rotated picture
  lp -o media=a4 -o orientation-requested=4 -o fitplot figure.ps
  • Print in fixed width format with awk
 echo $a $b $c |  awk '{for (i=1; i<=NF; i++) printf("%-20s ",$i);printf ("\n")}' > outfile.dat
where strings a,b,c may be entire lines.
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