I am trying to run simple script named test.sh which echo the numbers in ascending manner. But somehow it shows error.
#!/bin/bash
clear
a= 0
while [ $a <= 5 ];
do
echo $a
a=$(( a+1 ))
done
Error:
./test.sh: line 4: 0: command not found
./test.sh: line 6: =: No such file or directory
Way better is already mentioned by Anubhava, however this is correct version of your answer.
#!/bin/bash
clear
a=0
while [[ "$a" -lt 5 ]];
do
echo $a
a=$(($a+1))
done
<= instead -lt?
<= if you use the arithmetic statement: while (( a <= 5 )); do. bash doesn't have data types (all values are strings), so you need special commands and operators to specify whether you want to do string operations or treat the strings as integers.The first problem with your code is a= 0, spaces aren't allowed (before or after =) in assignment.
secondly, this part [ $a <= 5 ]. You have to use -lt instead of <= here.
As you are already familiar with the (( )) construct, I will recommend you to use that instead, which will let you compare integers with <=, >= etc..
Your code with the above modification:
#!/bin/bash
clear
a=0
while (( $a <= 5 ));
do
echo $a
a=$(( a+1 ))
done
for n in {1..5}; do echo "$n"; done