Old boy Education daily-70th Day-shell script optimization points:

Topic

See the following script:

#!/bin/bashgrep oldboy/etc/passwd &>/dev/nullreval=$?if [$REVAL-eq 0]then echo "Oldboy user already exists" else Useradd Oldboyfi

The above is a very simple creation of the corresponding user shell script code, is this simple script code can be more simple?

Reference Answer:

#!/bin/bashif grep-q oldboy/etc/passwdthen echo "Oldboy user already exists" else useradd Oldboyfi

User answer:

[' grep oldboy/etc/passwd|wc-l '-eq 1]&& echo OK | | Echo No

Note

Today is a day to accompany everyone's first day, look forward to your progress.
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Old boy Education daily-70th Day-shell script optimization points: