I'm trying to configure a file with a bash script. And the variables in the bash script are not written in file as it is written in script.
Ex:
#!/bin/bash
printf "%s" "template("$DATE\t$HOST\t$PRIORITY\t$MSG\n")" >> /file.txt
exit 0
This results to template('tttn') instead of template("$DATE\t$HOST\t$PRIORITY\t$MSG\n in file.
How do I write in the script so that the result is template("$DATE\t$HOST\t$PRIORITY\t$MSG\n in the configured file?
Is it possible to write variable as it looks in script to file?
Enclose the strings you want to write within single quotes to avoid variable replacement.
> FOO=bar
> echo "$FOO"
bar
> echo '$FOO'
$FOO
>
Using printf in any shell script is uncommon, just use echo with the -e option.
It allows you to use ANSI C metacharacters, like \t or \n. The \n at the end however isn't necessary, as echo will add one itself.
echo -e "template(${DATE}\t${HOST}\t${PRIORITY}\t${MSG})" >> file.txt
The problem with what you've written is, that ANSI C metacharacters, like \t can only be used in the first parameter to printf.
So it would have to be something like:
printf 'template(%s\t%s\t%s\t%s)\n' ${DATE} ${HOST} ${PRIORITY} ${MSG} >> file.txt
But I hope we both agree, that this is very hard on the eyes.