Getting the last argument passed to a shell script

Question

1 is the first argument     is all of them   How can I find the last argument passed to a shell script

User · Answer

Try the below script to find last argument

 # cat arguments.sh
 #!/bin/bash
 if [ $# -eq 0 ]
 then
 echo "No Arguments supplied"
 else
 echo $* > .ags
 sed -e 's/ /\n/g' .ags | tac | head -n1 > .ga
 echo "Last Argument is: `cat .ga`"
 fi

Output:

 # ./arguments.sh
 No Arguments supplied

 # ./arguments.sh testing for the last argument value
 Last Argument is: value

Thanks.

User · Answer

Use indexing combined with length of   echo               Note that this is bash-only

User · Answer

Here is mine solution    pretty portable  all POSIX sh  bash  ksh  zsh  should work does not shift original arguments  shifts a copy   does not use evil eval does not iterate through the whole list does not use external tools   Code   ntharg         shift  1     printf   s n    1    LAST ARG  ntharg

User · Answer

bin sh  next  1 while   -n    next       do   last  next   shift   next  1 done  echo  last

User · Answer

For bash  this comment suggested the very elegant   echo             As a bonus  this also works in zsh

User · Answer

To return the last argument of the most recently used command use the special parameter        In this instance it will work if it is used within the script before another command has been invoked

User · Answer

I found  AgileZebra s answer  plus  starfry s comment  the most useful  but it sets heads to a scalar  An array is probably more useful   heads        1       - 1       tail              Note that this is bash-only

User · Answer

The simplest answer for bash 3 0 or greater is    last                indirect reference  to the    variable   or  last  BASH ARGV    official built-in  but takes more typing      That s it     cat lastarg    bin bash   echo the last arg given   last       echo   last  last  BASH ARGV echo   last for x  do    echo  x done   Output is     lastarg 1 2 3 4  5 6 7  5 6 7 5 6 7 1 2 3 4 5 6 7

User · Answer

For tcsh   set X    echo      awk -F       print  NF    somecommand   X    I m quite sure this would be a portable solution  except for the assignment

User · Answer

Just use        mkdir folder   cd      will run  cd folder

User · Answer

There is a much more concise way to do this   Arguments to a bash script can be brought into an array  which makes dealing with the elements much simpler   The script below will always print the last argument passed to a script     argArray                                   Add all script arguments to argArray   arrayLength    argArray                    Get the length of the array   lastArg    arrayLength - 1                 Arrays are zero based  so last arg is -1   echo   argArray  lastArg     Sample output      lastarg sh 1 2 buckle my shoe shoe

User · Answer

This is a bit of a hack   for last  do true  done echo  last   This one is also pretty portable  again  should work with bash  ksh and sh  and it doesn t shift the arguments  which could be nice   It uses the fact that for implicitly loops over the arguments if you don t tell it what to loop over  and the fact that for loop variables aren t scoped  they keep the last value they were set to

User · Answer

After reading the answers above I wrote a Q amp D shell script  should work on sh and bash  to run g   on PGM cpp to produce executable image PGM  It assumes that the last argument on the command line is the file name   cpp is optional  and all other arguments are options      bin sh if      -lt 1   then     echo  Usage   basename  0   opt  pgm runs g   to compile pgm  cpp  into pgm      exit 2 fi OPT  PGM    PGM is the last argument  all others are considered options for F  do OPT   OPT  PGM   PGM  F  done DIR  dirname  PGM  PGM  basename  PGM  cpp    put -o first so it can be overridden by -o specified in OPT set -x g   -o  DIR  PGM  OPT  DIR  PGM cpp

User · Answer

If you want to do it in a non-destructive way  one way is to pass all the arguments to a function and return the last one      bin bash  last             if       -ne 0      then             shift   expr    - 1              echo   1           else              do something when no arguments         fi    lastvar   last       echo  lastvar echo       pax gt    qq sh 1 2 3 a b b 1 2 3 a b   If you don t actually care about keeping the other arguments  you don t need it in a function but I have a hard time thinking of a situation where you would never want to keep the other arguments unless they ve already been processed  in which case I d use the process shift process shift     method of sequentially processing them   I m assuming here that you want to keep them because you haven t followed the sequential method  This method also handles the case where there s no arguments  returning     You could easily adjust that behavior by inserting the commented-out else clause

User · Answer

A solution using eval   last   eval  echo         echo  last

User · Answer

The following will set LAST to last argument without changing current environment   LAST        shift      -1      echo  1    echo  LAST   If other arguments are no longer needed and can be shifted it can be simplified to   shift      -1   echo  1   For portability reasons following   shift      -1      can be replaced with   shift  expr    - 1    Replacing also     with backquotes we get   LAST       shift   expr    - 1      echo  1    echo  LAST

User · Answer

From oldest to newer solutions   The most portable solution  even older sh  works with spaces and glob characters   no loop  faster    eval printf    s n                    Since version 2 01 of bash    set -- The quick brown fox jumps over the lazy dog    printf   s n                      -1        -1       0         dog     dog dog dog dog   For ksh  zsh and bash     printf   s n        -1          0         the space beetwen                                                 and  -1  is a must  dog   dog   And for  next to last      printf   s n        1 1   lazy   Using printf to workaround any issues with arguments that start with a dash  like -n    For all shells and for older sh  works with spaces and glob characters  is     set -- The quick brown fox jumps over the lazy dog  the   last argument     eval printf    s n                The last   argument   Or  if you want to set a last var     eval last         printf   s n    last  The last   argument   And for  next to last      eval printf    s n              -1       dog

User · Answer

This is part of my copy function   eval echo   echo            To use in scripts  do this   a   eval echo   echo             Explanation  most nested first       echo          returns   nr  where  nr  is the number of parameters  E g  the string  123  unexpanded   echo  123 returns the value of 123rd parameter  when evaluated  eval just expands  123 to the value of the parameter  e g  last arg  This is interpreted as a string and returned    Works with Bash as of mid 2015

User · Answer

This works in all POSIX-compatible shells   eval last          Source  http   www faqs org faqs unix-faq faq part2 section-12 html

User · Answer

Found this when looking to separate the last argument from all the previous one s    Whilst some of the answers do get the last argument  they re not much help if you need all the other args as well  This works much better   heads     1   -1  tail           Note that this is bash-only

User · Answer

This is Bash-only   echo       -1

User · Answer

shift  expr    - 1  echo   1    This shifts the arguments by the number of arguments minus 1  and returns the first  and only  remaining argument  which will be the last one   I only tested in bash  but it should work in sh and ksh as well

User · Answer

Using parameter expansion  delete matched beginning    args      last   args        It s also easy to get all before last   prelast   args

User · Answer

echo  argv   argv    Now I just need to add some text because my answer was too short to post  I need to add more text to edit

User · Answer

If you are using Bash    3 0  echo   BASH ARGV 0

User · Answer

set quick brown fox jumps    echo      -1 1    last argument jumps    echo      -1    or simply jumps    echo      -2 1    next to last fox   The space is necessary so that it doesnt get interpreted as a default value   Note that this is bash-only

User · Answer

The following will work for you  The   is for array of arguments    means at     is the length of the array of arguments  So the result is the last element              Example   function afunction      echo            afunction -d -o local 50  Outputs 50   Note that this is bash-only

[shell] Getting the last argument passed to a shell script

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