COMP 3000 Lab 2 2010 - Revision history

Soma at 15:44, 8 November 2010

2010-11-08T15:44:47Z

← Older revision		Revision as of 15:44, 8 November 2010
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	The following lab requires access to a relatively standard Linux environment. Use a virtual machine version of Ubuntu or log in to one of the SCS Linux machines. Alternately, use your own Linux installation (installed natively or in a virtual machine).		The following lab requires access to a relatively standard Linux environment. Use a virtual machine version of Ubuntu or log in to one of the SCS Linux machines. Alternately, use your own Linux installation (installed natively or in a virtual machine).

	~~<b>Note - this lab is not yet finalized!</b>~~

	=Part A (Mandatory)=		=Part A (Mandatory)=

Zliu10: /* Help */

2010-10-06T17:18:11Z

Help

← Older revision		Revision as of 17:18, 6 October 2010
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	#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?		#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?
	~~A: echo deisplys a line of text~~
	#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?		#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?
	~~A: Change the location of the program break, which defines the end of the process' data segment.~~
	~~# What does the <tt>more</tt> command do?~~
	~~A: a filter for paging through text one screenful at a time.~~
	# How do you quit the <tt>less</tt> command?		# How do you quit the <tt>less</tt> command?
	~~A: allows backward movement in the file as well as forward movement~~

	===Shell Basics===		===Shell Basics===

Zliu10: /* Dynamic Libraries */

2010-09-28T15:25:30Z

Dynamic Libraries

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	# Using <tt>ldd</tt>, what dynamic library dependencies does the <tt>top</tt> command have?		# Using <tt>ldd</tt>, what dynamic library dependencies does the <tt>top</tt> command have?
	# In addition to the libraries listed as dependencies for the application <tt>top</tt> by <tt>ldd</tt>, there may be other libraries that the application loads dynamically at run-time. Retrieve the process number <em>PID</em> for the <tt>bash</tt> process (using <tt>ps</tt>) and examine the map file located at <tt>/proc/</tt><em>PID</em><tt>/maps</tt>. What other dynamic libraries have been loaded into the application while it has been running?		# In addition to the libraries listed as dependencies for the application <tt>top</tt> by <tt>ldd</tt>, there may be other libraries that the application loads dynamically at run-time. Retrieve the process number <em>PID</em> for the <tt>bash</tt> process (using <tt>ps</tt>) and examine the map file located at <tt>/proc/</tt><em>PID</em><tt>/maps</tt>. What other dynamic libraries have been loaded into the application while it has been running?

			Linux-gate.so.1, libproc, libncurses, libc, libdl, /lib/ld-linux

	=Part B (Optional)=		=Part B (Optional)=

Zliu10: /* Environment */

2010-09-28T15:16:23Z

Environment

← Older revision		Revision as of 15:16, 28 September 2010
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	What does the export command seem to do?		What does the export command seem to do?
			declare a global variable

	==Dynamic Libraries==		==Dynamic Libraries==

Zliu10: /* Shell Basics */

2010-09-28T15:12:02Z

Shell Basics

← Older revision		Revision as of 15:12, 28 September 2010
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	# The <tt>ps</tt> command is used to get a list of processes which are running on the system. Start a new shell from bash by running <tt>bash</tt>. Does the new shell replace or run in parallel with the old BASH shell? What about <tt>exec bash</tt>? You can use the <tt>ps</tt> command to determine if bash is still running.		# The <tt>ps</tt> command is used to get a list of processes which are running on the system. Start a new shell from bash by running <tt>bash</tt>. Does the new shell replace or run in parallel with the old BASH shell? What about <tt>exec bash</tt>? You can use the <tt>ps</tt> command to determine if bash is still running.
	# Because each process is started by some other process, there is a process tree structure on the system. From within your bash terminal, determine what process started BASH by using the <tt>pstree</tt> command. What graphical application can give you the same information?		# Because each process is started by some other process, there is a process tree structure on the system. From within your bash terminal, determine what process started BASH by using the <tt>pstree</tt> command. What graphical application can give you the same information?
			/usr/bin/top
			tcsh
			ls -a
			bash: open a new one.
			exec bash: replace the old one
			init--gnome-terminal--bash

	==Processes==		==Processes==

Wlawrenc: /* Dynamic Libraries */

2010-09-28T15:01:31Z

Dynamic Libraries

← Older revision		Revision as of 15:01, 28 September 2010
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	# Using <tt>ldd</tt>, what dynamic library dependencies does the <tt>top</tt> command have?		# Using <tt>ldd</tt>, what dynamic library dependencies does the <tt>top</tt> command have?
	# In addition to the libraries listed as dependencies for the application <tt>top</tt> by <tt>ldd</tt>, there may be other libraries that the application loads dynamically at run-time. Retrieve the process number <em>PID</em> for the <tt>bash</tt> process (using <tt>ps</tt>) and examine the ~~mmap~~ file located at <tt>/proc/</tt><em>PID</em><tt>/maps</tt>. What other dynamic libraries have been loaded into the application while it has been running?		# In addition to the libraries listed as dependencies for the application <tt>top</tt> by <tt>ldd</tt>, there may be other libraries that the application loads dynamically at run-time. Retrieve the process number <em>PID</em> for the <tt>bash</tt> process (using <tt>ps</tt>) and examine the map file located at <tt>/proc/</tt><em>PID</em><tt>/maps</tt>. What other dynamic libraries have been loaded into the application while it has been running?


	=Part B (Optional)=		=Part B (Optional)=

Zliu10: /* Permissions */

2010-09-28T15:00:52Z

Permissions

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	#Who is the owner of the <tt>/etc</tt> directory?		#Who is the owner of the <tt>/etc</tt> directory?
			A: root
	# What group is associated with the <tt>/etc/shadow</tt> file?		# What group is associated with the <tt>/etc/shadow</tt> file?
			A: shadow
	# Each user is a member of some number of groups. You can determine what groups you are part of by using the <tt>groups</tt> command. Based on the groups listed, would you (the ``student'' user in the lab) be a member of the group associated with the <tt>/etc/shadow</tt> file?		# Each user is a member of some number of groups. You can determine what groups you are part of by using the <tt>groups</tt> command. Based on the groups listed, would you (the ``student'' user in the lab) be a member of the group associated with the <tt>/etc/shadow</tt> file?
			A: no

	==Environment==		==Environment==

Zliu10: /* Help */

2010-09-28T14:54:51Z

Help

← Older revision		Revision as of 14:54, 28 September 2010
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	#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?		#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?
			A: echo deisplys a line of text
	#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?		#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?
			A: Change the location of the program break, which defines the end of the process' data segment.
	# What does the <tt>more</tt> command do?		# What does the <tt>more</tt> command do?
			A: a filter for paging through text one screenful at a time.
	# How do you quit the <tt>less</tt> command?		# How do you quit the <tt>less</tt> command?
			A: allows backward movement in the file as well as forward movement
	~~1.echo - display a line of texts.~~
	~~2.brk,sbrk - change data segment size~~
	~~3.more -~~ file ~~perusal filter for crt viewing~~

	===Shell Basics===		===Shell Basics===

Rannath: Undo revision 2265 by Rannath (Talk)

2010-09-28T14:54:42Z

Undo revision 2265 by Rannath (Talk)

← Older revision		Revision as of 14:54, 28 September 2010
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	===Help===		===Help===

	~~# How do you quit the <tt>less</tt> command?~~
	#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?		#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?
	#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?		#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?
	# What does the <tt>more</tt> command do?		# What does the <tt>more</tt> command do?
			# How do you quit the <tt>less</tt> command?

	1.echo - display a line of texts.		1.echo - display a line of texts.

Rannath at 14:52, 28 September 2010

2010-09-28T14:52:26Z

← Older revision		Revision as of 14:52, 28 September 2010
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	===Help===		===Help===

			# How do you quit the <tt>less</tt> command?
	#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?		#When working in the shell, help is available on most programs in the system, especially those that are command line based. This system of help is available by using the <tt>man</tt> command. If one wanted to get help on the echo command, the associated command would be <tt>man echo</tt>. What does <tt>man</tt> stand for?
	#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?		#The <tt>man</tt> command can also be used to get help on standard C functions. Briefly (in one line), what does the C function <tt>brk</tt> do?
	# What does the <tt>more</tt> command do?		# What does the <tt>more</tt> command do?
	~~# How do you quit the <tt>less</tt> command?~~

	1.echo - display a line of texts.		1.echo - display a line of texts.