Shell Programming and Scripting

sh -x test.sh > output.txt 2>&1

$ sh -x test.sh >& output.txt
ksh: >&output.txt : illegal file descriptor name

kamaraj@kamaraj-laptop:~/Desktop/testing$ head sample.sh
#!/bin/sh -x
cat sample.txt | awk ' /./ {print $1}' | sort | uniq > output.txt

for i in `cat output.txt`;do 
    tot=0;
    num=`grep $i sample.txt|awk '{print$2}'`; 
        for j in $num;do 
            tot=`expr $j + $tot`;
        done;
    echo "$i --> $tot"; 
kamaraj@kamaraj-laptop:~/Desktop/testing$ ./sample.sh >& shell_output
kamaraj@kamaraj-laptop:~/Desktop/testing$ head shell_output 
+ cat sample.txt
+ awk  /./ {print $1}
+ sort
+ uniq
+ cat output.txt
+ tot=0
+ grep kamaraj sample.txt
+ awk {print$2}
+ num=34
35