Today I'm learning make command, and I find it seems can execute any bash command by reading Makefile on current directory.
However, I encountered a problem. That when using variables, it seems that system will only read the first character of the variable.
Below is my file and running result:
# FILE CONTENT
Z="zen_on_the_moon"
now=$(date)
fun:
touch $Z
echo $now
echo "file created on" $now >> $Z
# RUNNING IT
=>make fun
touch "zen_on_the_moon"
echo ow
ow
echo "file created on" ow >> "zen_on_the_moon"
How should I use the variable now in the Makefile under fun item?
In Makefile, you refer to a variable by using syntax $(var_name). Using $var_name cause the first character other than a dollar sign $, open parenthesis ( or open brace { treated as variable name.
In $now, you actually get content of variable $n followed by literal string ow.
So you need:
$(now)
to get the content of variable named now.
Also note that now=$(date) get the content of variable named date instead of result of command date. You need to use shell function:
now=$(shell date)
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