Help with the functionality of the last (&/or who) command. Post: 302577747

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Top Forums UNIX for Dummies Questions & Answers Help with the functionality of the last (&/or who) command. Post 302577747 by agama on Tuesday 29th of November 2011 09:15:06 PM

11-29-2011

Registered User

This is a hack, and probably not the way I'd do it for anything other than a quick script, but it uses last to print the last 'n days' worth of users who were logged in. Prevents dups if a user logs in more than once per day and will not work with a BSD version of last.

Code:

#!/usr/bin/env ksh
# $1 from command line is number of days to go back; assuming someone 
# logged in each day (doesn't handle days where nobody logged in)

last -F -R | awk '
    BEGIN { soup = "JanFebMarAprMayJunJulAugSepOctNovDec"; }

    NF < 6 || /reboot/ || /begins/ || /still logged/ {next;}   # skip rubbish

    {
        m = int(index( soup, $4 ) / 3) + 1;     #convert month name to int
        d = sprintf( "%4d%02d%02d", $7, m, $5 );   # build a sortable date
        if( ! seen[d,$1]++ )
            who[d] = who[d] $1 " ";            # create user list by date
    }

    END {
        for( w in who )                 # for each user list print
            print w, who[w];
    }
' | sort -k 1n,1 | tail -${1:-15}
exit

Last edited by agama; 11-29-2011 at 10:16 PM.. Reason: typo

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RBASH(1)						      General Commands Manual							  RBASH(1)

NAME

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RESTRICTED SHELL

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       used to set up an environment more controlled than the standard shell.  It behaves identically to bash with the exception that the  follow-
       ing are disallowed or not performed:

       o      changing directories with cd

       o      setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV

       o      specifying command names containing /

       o      specifying a file name containing a / as an argument to the .  builtin command

       o      specifying a filename containing a slash as an argument to the -p option to the hash builtin command

       o      importing function definitions from the shell environment at startup

       o      parsing the value of SHELLOPTS from the shell environment at startup

       o      redirecting output using the >, >|, <>, >&, &>, and >> redirection operators

       o      using the exec builtin command to replace the shell with another command

       o      adding or deleting builtin commands with the -f and -d options to the enable builtin command

       o      using the enable builtin command to enable disabled shell builtins

       o      specifying the -p option to the command builtin command

       o      turning off restricted mode with set +r or set +o restricted.

       These restrictions are enforced after any startup files are read.

       When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script.

SEE ALSO

       bash(1)

GNU Bash-4.0							    2004 Apr 20 							  RBASH(1)

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