UNIX for Dummies Questions & Answers

bbb
ccc
aaa

aaa|12
bbb|23
ccc|43

while read line;
do
   mapped= ??AWK $line mapping.txt
   ....
   ....
done < input_string.txt

#! /bin/bash
while read x
do
    mapped=`grep $x output`
    echo ${mapped#*|}
done < input_string.txt

awk -F'|' 'BEGIN { while(getline<"mapping.txt") A[$1]=$2 }; A[$1] { print A[$1] }' input_string.txt

# Code in BEGIN block gets run before all lines are read
# Read from the map file, set array based on contents
A["aaa"]=12
A["bbb"]=23
A["ccc"]=43

# For every line in the array, print the array's contents
print A["bbb"]
print A["ccc"]
print A["aaaa"]

awk -F'|' 'BEGIN { while(getline<"mapping.txt") A[$1]=$2 }; A[$1] { print A[$1] }' input_string.txt

while read line; 
do    
   mapped=A["$line"]
   ....    .... 
done < input_string.txt

$ cat mapping.txt
aaa|12
bbb|23
ccc|43

$ cat input_string.txt
bbb
ccc
aaa

$ awk -F'|' 'BEGIN { while(getline<"mapping.txt") A[$1]=$2 }; A[$1] { print A[$1] }' input_string.txt
23
43
12

$