13,420
edits
Changes
→INVESTIGATION 2: FILE PERMISSIONS
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">chmod 750 -R ~/documents</span><br><br>
# Again, use the '''ls''' command to confirm the permissions for the '''~/documents''', '''~/document/memos''' , '''~/documents/reports''', and '''~/documents/contracts''' directories.<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">ls -lR ~/documents</span><br>What do you noticed happened to the permissions for the regular files contained in those directories. <br>Did those regular file permissions change?<br><br>We want to now change those regular file permissions to the following settings: <span style="font-weight:bold;font-family:courier;">r w - r - - - - -</span><br><br>
# Issue the following Linux commands: <br><span style="color:blue;font-weight:bold;font-family:courier;">chmod 640 ~/documents/memos/memo*.txt<br>chmod 640 ~/documents/reports/report*.txt<br>chmod 640 ~/dcouments/contracts/contract*.txt</span><br><br>
# Issue the '''ls -lR''' command for the '''~/documents''' directory to confirm that those regular file permission have changed.<br><br>Let's get some practice setting permissions to allow users to make editing changes to regular files.<br><br>
# Issue the following Linux command to view permissions for your '''home''' directory: <span style="color:blue;font-weight:bold;font-family:courier;">ls -ld ~</span><br><br>What does execute permissions mean for same group members and other group members in terms of your '''home''' directory?<br><br>
# Issue the following Linux command to create a new subdirectory: <span style="color:blue;font-weight:bold;font-family:courier;">mkdir ~/shared</span><br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">ls -l ~/shared</span><br><br>What are the permissions for this newly-created directory? <br>Can other users access the directory pathname '''~youruserid/shared''' ?<br><br>
# Issue the following Linux command (without an argument): <span style="color:blue;font-weight:bold;font-family:courier;">umask</span><br><br>'''NOTE:''' You should see a '''four-digit octal''' number. Drop the leading zero on the left to obtain the '''default umask value'''.<br><br>
# Perform a '''mathematical calculation ''' by taking the octal number '''777''' and subtracting the default umask value you determined in the previous step.<br>What is the result?<br><br>
# Convert that octal number result to a '''binary''' number. What does that represent as newly created directory permissions?<br>Does that correspond to the permissions for the newly created '''~/shared''' directory?<br><br>
# Repeat '''steps #27''' and '''#28''' to see how a umask setting of '''077''' would affect permissions of newly-created directories.<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">umask 077</span><br><br>
# Issue the following Linux command (without arguments): <span style="color:blue;font-weight:bold;font-family:courier;">umask</span><br><br>NOTE: You should notice the value '''0077'''. By dropping the leading zero to the left, that would provide the default '''umask value of 077'''.<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">mkdir ~/shared2</span><br><br>
