The following bash script works fine to print numbers from 1 to 10:
for i in {1..10}
do
echo "$i"
done
But if I want to make the upper limit a variable, then this script does not works.
i=10
for j in {1..$i}
do
echo "$j"
done
Can anyone suggest please how to make the second script work?
Brace expansion happens before any other expansion.
You can say:
for j in $(seq 1 $i); do echo "$j"; done
Quoting from the link above:
Brace expansion is performed before any other expansions, and any characters special to other expansions are preserved in the result. It is strictly textual. Bash does not apply any syntactic interpretation to the context of the expansion or the text between the braces. To avoid conflicts with parameter expansion, the string
‘${’is not considered eligible for brace expansion.
seq command since I could never use it on my Mac.
sudo rm -f $(which seq) and have forgotten doing so!You cannot use variables in {..} directive of Bash. Use BASH arithmetic operator ((...)) like this:
i=10
for ((j=1; j<=i; j++)); do
echo "$j"
done
