1 | <sect2>
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2 | <title>Contents</title>
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3 |
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4 | <para>The Sysvinit package contains the pidof, last, lastb, mesg, utmpdump,
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5 | wall, halt, init, killall5, poweroff, reboot, runlevel, shutdown,
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6 | sulogin and telinit programs.</para>
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7 |
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8 | </sect2>
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9 |
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10 | <sect2><title>Description</title>
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11 |
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12 | <sect3><title>pidof</title>
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13 |
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14 | <para>Pidof finds the process id's (pids) of the named programs and prints
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15 | those id's on standard output.</para>
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16 |
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17 | </sect3>
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18 |
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19 | <sect3><title>last</title>
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20 |
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21 | <para>last searches back through the file /var/log/wtmp (or the file designated
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22 | by the -f flag) and displays a list of all users logged in (and out)
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23 | since that file was created.</para>
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24 |
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25 | </sect3>
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26 |
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27 | <sect3><title>lastb</title>
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28 |
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29 | <para>lastb is the same as last, except that by default it shows a log of the
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30 | file /var/log/btmp, which contains all the bad login attempts.</para>
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31 |
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32 | </sect3>
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33 |
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34 | <sect3><title>mesg</title>
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35 |
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36 | <para>Mesg controls the access to the users terminal by others. It's typically
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37 | used to allow or disallow other users to write to his terminal.</para>
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38 |
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39 | </sect3>
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40 |
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41 | <sect3><title>utmpdump</title>
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42 |
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43 | <para>utmpdumps prints the content of a file (usually /var/run/utmp) on
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44 | standard output in a user friendly format.</para>
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45 |
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46 | </sect3>
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47 |
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48 | <sect3><title>wall</title>
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49 |
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50 | <para>Wall sends a message to everybody logged in with their mesg permission
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51 | set to yes.</para>
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52 |
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53 | </sect3>
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54 |
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55 | <sect3><title>halt</title>
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56 |
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57 | <para>Halt notes that the system is being brought down in the file
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58 | /var/log/wtmp, and then either tells the kernel to halt, reboot or
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59 | poweroff the system. If halt or reboot is called when the system is not
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60 | in runlevel 0 or 6, shutdown will be invoked instead (with
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61 | the flag -h or -r).</para>
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62 |
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63 | </sect3>
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64 |
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65 | <sect3><title>init</title>
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66 |
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67 | <para>Init is the parent of all processes. Its primary role is to create
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68 | processes from a script stored in the file /etc/inittab. This
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69 | file usually has entries which cause init to spawn gettys on each line that
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70 | users can log in. It also controls autonomous processes required by any
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71 | particular system.</para>
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72 |
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73 | </sect3>
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74 |
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75 | <sect3><title>killall5</title>
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76 |
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77 | <para>killall5 is the SystemV killall command. It sends a signal to all
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78 | processes except the processes in its own session, so it won't kill the
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79 | shell that is running the script it was called from.</para>
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80 |
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81 | </sect3>
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82 |
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83 | <sect3><title>poweroff</title>
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84 |
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85 | <para>poweroff is equivalent to shutdown -h -p now. It halts the computer and
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86 | switches off the computer (when using an APM compliant BIOS and APM is
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87 | enabled in the kernel).</para>
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88 |
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89 | </sect3>
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90 |
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91 | <sect3><title>reboot</title>
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92 |
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93 | <para>reboot is equivalent to shutdown -r now. It reboots the computer.</para>
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94 |
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95 | </sect3>
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96 |
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97 | <sect3><title>runlevel</title>
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98 |
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99 | <para>Runlevel reads the system utmp file (typically /var/run/utmp) to locate
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100 | the runlevel record, and then prints the previous and current system
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101 | runlevel on its standard output, separated by a single space.</para>
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102 |
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103 | </sect3>
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104 |
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105 | <sect3><title>shutdown</title>
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106 |
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107 | <para>shutdown brings the system down in a secure way. All logged-in users are
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108 | notified that the system is going down, and login is blocked.</para>
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109 |
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110 | </sect3>
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111 |
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112 | <sect3><title>sulogin</title>
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113 |
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114 | <para>sulogin is invoked by init when the system goes into single user mode
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115 | (this is done through an entry in /etc/inittab). Init also tries to
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116 | execute sulogin when it is passed the -b flag from the boot loader
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117 | (eg, LILO).</para>
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118 |
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119 | </sect3>
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120 |
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121 | <sect3><title>telinit</title>
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122 |
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123 | <para>telinit sends appropriate signals to init, telling it which runlevel to
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124 | change to.</para>
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125 |
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126 | </sect3>
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127 |
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128 | </sect2>
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129 |
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