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I'm using the following line to create a randomly generated password in a bash script, but it doesn't look like the string is actually being set to the variable.

#Generate random password
PASSWORD=date+%s|sha256sum|base64|head -c 32;

When I reference $PASSWORD later in this script, drush complains that I didn't supply a password. To test, I've tried a few "echoes" to confirm my suspicion. Does it look there's something off in my assignment statements?

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Use syntax VAR=$(command). – enedil Jul 18 '14 at 14:58
A tip on 'random' things that might be used as a password, check man mktemp and note the --dry-run option, it is stated as "unsafe" with regard to creating temporary files... but may suit your needs quite well. – Hannu Jul 18 '14 at 15:09

3 Answers 3

up vote 5 down vote accepted

You need to use a command substitution quotation, like

PASSWORD=`date +%s|sha256sum|base64|head -c 32`

or you can do it as,

PASSWORD=$(date +%s|sha256sum|base64|head -c 32)
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The second type is preferred, as it is more visual/visible and also allows nesting to be done easily. – Hannu Jul 18 '14 at 15:00

You have to use a command substitution:

#Generate random password
PASSWORD=$(date +%s|sha256sum|base64|head -c 32)

then it should work.

Prefer the "$" sign, read more here: Using backticks or dollar in shell scripts

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Darn, wish I could mark two answers! – sean Jul 18 '14 at 14:59
You can upvote ;-) – Hannu Jul 18 '14 at 15:10

Generating a password just based on the current time is quite bad.

As you want a 32-character password, I would do something like this:

PASSWORD=$(head -c 16  /dev/random | md5sum | cut -f 1 -d\ )
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or just use pwgen – tomodachi Jul 28 '14 at 13:54

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