2002-04-01 16:05:47 +00:00
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#!/bin/bash
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# userlist.sh
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PASSWORD_FILE=/etc/passwd
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n=1 # User number
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2014-07-05 13:38:40 +00:00
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for name in $(awk 'BEGIN{FS=":"}{print $1}' < "$PASSWORD_FILE" )
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2002-04-01 16:05:47 +00:00
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# Field separator = : ^^^^^^
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# Print first field ^^^^^^^^
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2012-11-27 14:56:18 +00:00
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# Get input from password file /etc/passwd ^^^^^^^^^^^^^^^^^
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2002-04-01 16:05:47 +00:00
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do
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echo "USER #$n = $name"
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let "n += 1"
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done
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# USER #1 = root
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# USER #2 = bin
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# USER #3 = daemon
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# ...
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2012-11-27 14:56:18 +00:00
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# USER #33 = bozo
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2002-04-01 16:05:47 +00:00
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2011-08-29 23:59:19 +00:00
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exit $?
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2005-05-08 20:09:31 +00:00
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2011-08-29 23:59:19 +00:00
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# Discussion:
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# ----------
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# How is it that an ordinary user, or a script run by same,
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#+ can read /etc/passwd? (Hint: Check the /etc/passwd file permissions.)
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2012-11-27 14:56:18 +00:00
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# Is this a security hole? Why or why not?
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