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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hello professor,</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">According to the slide 4 of Lecture 06, the login shell which named “-sh” would directly fork and exec.<o:p></o:p></p>
<p class="MsoNormal">But when I run “ps” command, it shows like this:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">USER PID PPID PGID SESS JOBC STAT TTY TIME COMMAND<o:p></o:p></p>
<p class="MsoNormal">g_cream 1158 1363 1363 a14620 0 S ? 0:00.01 sshd: g_cream@pts/0 (sshd)<o:p></o:p></p>
<p class="MsoNormal">root 811 1391 811 a14968 1 S pts/0 0:00.04 sh<o:p></o:p></p>
<p class="MsoNormal">g_cream 1391 1158 1391 a14968 0 Is pts/0 0:00.00 -sh<o:p></o:p></p>
<p class="MsoNormal">root 2804 811 2804 a14968 1 O+ pts/0 0:00.00 ps -ajx<o:p></o:p></p>
<p class="MsoNormal">g_cream 40 755 40 df3930 1 I ttyE0 0:00.01 -sh<o:p></o:p></p>
<p class="MsoNormal">root 41 40 41 df3930 1 I+ ttyE0 0:00.05 sh<o:p></o:p></p>
<p class="MsoNormal">root 755 1 755 df3930 0 Is ttyE0 0:00.04 login<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">1.It seems the login shell will fork a process named “sh”, and then this “sh” forks to run the command.<o:p></o:p></p>
<p class="MsoNormal">2.The shell process we used to type in the command should be the “sh” not “-sh”.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is this right or I misunderstand some steps of this?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Yuxi Wang</p>
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