Linux in a Nutshell, Fifth Edition

useradd | 493

Linux

Commands

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-D, --all-repeated[=method]

Print all duplicate lines. -D takes no delimiter method. The

delimiter method method takes one of the following values:

none (default), prepend,orseparate. Blank lines are used as

the delimiter.

-f n, --skip-fields=n

Ignore first n fields of a line. Fields are separated by spaces or

by tabs.

-i, --ignore-case

Ignore case differences when checking for duplicates.

-s n, --skip-chars=n

Ignore first n characters of a field.

-u, --unique

Print only unique lines (no copy of duplicate entries is kept).

-w n, --check-chars=n

Compare only first n characters per line (beginning after

skipped fields and characters).

--help

Print a help message and then exit.

--version

Print version information and then exit.

Examples

Send one copy of each line from list to output file list.new:

uniq list list.new

Show which names appear more than once:

sort names | uniq -d

uptime

uptime [option]

Print the current time, how long the system has been running, the

number of users currently logged in (which may include the same

user multiple times), and system load averages. This output is also

produced by the first line of the w command.

Option

-V Print version information and exit.

useradd

useradd [options] [user]

System administration command. Create new user accounts or

update