无法在Bash中正确读取文件

Question

I have a test.csv file which looks as below

LOC,IP,D1,D2
abc1,10.13|10.12|10.13|10.14|10.15|10.16,10.11.1.1,11.1.1.23
abc2,12.11|10.15|10.116|10.127|10.110,11.110.8.25,11.11.5.3
abc3,13.21|13.2,10.1.4.50,10.2.7.3

I want to calculate Ipaddress on the target server and then check if the ipaddress matches the value in test.csv file. If it matches then I want to call check_func and pass values of D1 and D2 to that function.

So far, I am able to calculate ipaddress using the following command

host=`uname -n'`
ip_addr=`host $host | awk '{print $NF}'`

Now, I want to do something like below:

case $ip_addr in
      10.11|10.12|10.13|10.14|10.15|10.16)
             check_func "10.11.1.1" "11.1.1.23"

I have written the following script but it is not giving correct result. I am always getting the output Unknown.

#! /bin/bash
shopt -s extglob
IFS_backup=$IFS
IFS=,
while read -r column1 column2 column3 column4 ; do
   shopt -s extglob
   case "$ip_addr" in
      @($column2)) check_func "$column3" "$column4" ;;
      *) echo Unknown. ;;
   esac
done < file.csv

Answer 1

Glob matches need to be exact. A prefix or substring match won't trigger the case clause.

So you probably want

@($column2)*) check_func "$column3" "$column4" ;;

which effectively accepts a prefix match of any of the alternatives.

By the way, a cleaner way to set IFS for just the read statement is

while IFS=, read -r column1 column2 column3 column4 ; do

That just sets IFS for the environment of the read command, so you don't need to worry about it affecting the rest of the script.

Answer 2

Try something like this instead:

host=$(uname -n)
awk -F, -v ip_addr="$(host "$host")" '
    BEGIN { sub(/.*[[:space:]]/,"",ip_addr) }
    { gsub(/\./,"[.]",$2) }
    ip_addr ~ $2 { print $3, $4; f=1 }
    END { if (!f) print "Unknown" | "cat>&2" }
' file.csv |
xargs -n 2 check_func

Untested of course since you didn't provide a complete set of sample input/output we could test against but hopefully it's close enough for you to fix if it's not exactly right.