mjhjmtu

I have a variable set with var='type_cardio_10-11-2017'. I need to remove the last 10 letters from the variable, and append the remaining value to var2.

I tried with the following script, but it doesn't work as expected.

var=type_cardio_10-11-2017
var2=$var | cut -f1 -d "_"
echo $var2

The output I want is type_cardio.

To remove everything from after the last _ in var and assign the result to var2:

var2=$var%_*

The parameter expansion $parameter%word removes the pattern word (_* in this case) from the end of the value of the given variable.

The POSIX standard calls this a "Remove Smallest Suffix Pattern" parameter expansion.

You actually want to remove the trailing 11 characters from the string; here's another way to do it:

$ var=type_cardio_10-11-2017
$ var2=$var%???????????
$ echo "$var2"
type_cardio

Another approach in bash:

echo "$var::-10"

Or in older versions:

echo "$var::$#var-10" #or
echo "$var: : -10"

1) bash solution:

var1="type_cardio_10-11-2017"
var2=$var1%_*

2) cut solution:

var1="type_cardio_10-11-2017"
var2=$(cut -d'_' -f1,2 <<<"$var1")
echo "$var2"

The output:

type_cardio

Appending var and var2 is the easy part - you can just join them like new_var="$var$var2". If what you really meant to say is you want to store cropped var into var2,then it's just var2=$(...) and you can put the commands that other users and my answer presented here inside the $() portion.

The main part is removing those 10 characters. There's number of ways to extract the part you want from var:

• 
  

  printf (pretty portable, doesn't rely on specific shell)

  
  
  

  $ printf "%.11sn" "$var" 
  type_cardio
  

  
  


• 
  

  awk

  
  
  

  $ var=type_cardio_10-11-2017 
  $ awk -v awk_var="$var" 'BEGINprint substr(awk_var,0,length(awk_var)-11)' 
  type_cardio
  

  
  
  

  or you can use printf trick here as well:

  
  
  

  $ echo "$var" | awk 'printf "%.11sn",$0' 
  type_cardio
  

  
  


• 
  

  egrep

  
  
  

  $ echo "$var" | egrep -o '^.0,11' 
  type_cardio
  

  
  


• 
  

  perl:

  
  
  

  $ echo "$var" | perl -lne 'print substr($_,0,11)' 
  type_cardio
  

  
  


• 
  

  python:

  
  
  

  $ python -c 'import sys;print sys.argv[1][0:11] ' "$var" 
  type_cardio