LinuxQuestions.org - printf field width

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- - printf field width (https://www.linuxquestions.org/questions/programming-9/printf-field-width-507203/)

printf field width

hello, here is a code that formats output of "mount" command:

Code:

#!/bin/bash

# mount table format



case "$#" in

0)      cat /etc/mtab | awk 'BEGIN      { print "filesystem mount              type" }

                                        { printf "%10s %-20s %-12s %s\n", $1, $2, $3, $4 }'

        ;;

*)      mount "$@"

        ;;

esac

fields are with defined width, and when i mount something that is wider ( iso image as loop )
it moves the other fields to the right...
i saw that "df" command prints first field and then prints other fields on the next line and they keep their position...
how to do this with "printf", or in other way??

Try this one ...

Code:

#!/bin/bash

# mount table format



case "$#" in

0)      cat /etc/mtab | awk 'BEGIN { 

                              print "filesystem mount              type" 

                            }

                            {

                              line[NR]=$0; 

                              if(length($1)>longest){

                                longest = length($1)

                              }

                            }  

                            END{ 

                              for(i in line){ 

                                split(line[i],chunks);

                                j="%-"longest+1"s %-20s %-12s %s\n"; 

                                printf j, chunks[1], chunks[2], chunks[3], chunks[4] 

                              }

                            }'

        ;;

*)      mount "$@"

        ;;

esac

Cheers,
Tink

insted of script now i use
mount | column -t