In my environment:
THE_KEY="Bearer ABCDEFGHI"
and here is some_script.sh
#!/bin/sh
./yet_other_script.sh "$(echo $THE_KEY)"
which calls yet_other_script.sh such that parameter $1 is Bearer ABCDEFGHI
Is there a simpler way than "$(echo $THE_KEY)"?
Replace:
./yet_other_script.sh "$(echo $THE_KEY)"
with:
./yet_other_script.sh "$THE_KEY"
Consider a directory with these files:
$ ls file*
file file1 file2 file3
Define the variable:
$ TheKey="a file?"
Now, watch what echo $TheKey does:
$ echo $TheKey
a file1 file2 file3
The multiple spaces between a and file have been collapsed. This is the result of word splitting. Also, the string has been subjected to pathname expansion resulting in file? being replaced by the names of files.
In sum, unless you explicitly want the shell to perform expansions, always put your shell variables in double-quotes:
$ echo "$TheKey"
a file?
That's not all: Command substitution removes trailing newlines from the output of the command. For example:
$ TheKey=$'abc\n\n\n'
$ echo "$(echo "$TheKey")"
abc
$
There are many ways to pass a value from one script to another:
./script.sh "$key" - the value is available as $1 within script.sh.echo "$key" | ./script.sh - the value can be read for example using the read built-in command.As an exported variable:
export KEY
./script.sh
$KEY is then available with the same name in script.sh.
key=value) is stored.The naming conventions are intentional: by convention upper case names should only be used for exported variables.
