Shell Programming and Scripting

2017-07-12_gmr_tag_log_20170711.csv
2017-07-12_gmr_call_log_20170711.csv
2017-07-12_gmr_outgoing_log_20170711.csv

gmr_tag_log.csv
gmr_call_log.csv
gmr_outgoing_log.csv

sed 's/[^_]*_//; s/_[^._]*[.]\(.*\)$/.\1/' infile

#run interactively
 a="2017-07-12_gmr_tag_log_20170711.csv" 
 echo $a                                 
#remove the first 11 characters           
b=${a:11}                               
echo $b
#set l to the length of string b
 l=${#b}                                 
echo $l
#set s to the middle length of string b
let s=$l-13                             
echo $s
#set c to the middle part of the string  
c=${b:0:$s}                             
echo $c                                 
#concatenate string c and ".csv"         
d=$c.csv                                
echo $d

#!/bin/bash
for file in *.csv
do
   len=${#file}
   let len=$len-11-13
   outfile=${file:11:$len}
   cp $file outdir/$outfile.csv
done