List of commands covered in this document
cal display a calendar
cat display or join files
cd change directory
chmod change permissions of a file or directory
cp copy a file
date display the date
find find a file
lp print to a Marquette MSCS printer
ls list the files in a directory
man access the online manual
mkdir create a directory
mv move or rename a file
pwd list the present working directory
rm remove or delete a file
rmdir remove or delete a directory
telnet connect to a remote computer over a network
To display a calendar:
- cal [month] [year] displays a calendar for integer month and integer year , if specified.
- Example 1: cal 12 1998 displays a calendar for December, 1998
- Example 2: cal 1998 displays a calendar for 1998
- Example 3: cal displays a calendar for the current year.
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To display or join files:
- cat file1 displays a copy of file1 on the screen.
- Example 1: cat Bank.java displays Bank.java on the screen.
- Example 2: cat Bank.java Account.java displays Bank.java and Account.java on the screen.
- Example 3: cat Bank.java Account.java > assignment concatenates(joins) Bank.java and Account.java and redirects the output to the file assignment. i.e. a new file is created which contains both Bank.java and Account.java
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To change directory:
- cd dir changes the current directory to dir
- Example 1: cd ECR/Bank changes the current directory to ECR/Bank
- Example 2: cd .. changes the current directory to the parent directory.
- Example 3: cd changes the current directory to the home directory no matter what the present working directory.
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To change access permissions :
- chmod who operation permissions file/directory adds or deletes permissions on a file or directory for various groups of users.
- who :
- u - owner of the file
g - group to which the owner belongs
o - all other users
a - all users
operations :
- + - add
- - delete
permissions :
- r - read permission
w - write permission
x - execute permission
- Example 1: chmod go-rwx ECR deletes read, write and execute permissions on the directory ECR for all persons except the owner.
- Example 2: chmod u+x bin/noctrlM adds execute permission to the file bin/noctrlM for the owner.
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To copy a file:
- cp file1 file2 creates a copy of file1 called file2
- Example 1: cp letter form creates a copy of letter, called form.
- cp file1 dir creates a copy of file1 in the directory dir, keeping the same name.
- Example 2: cp letter Archive creates a copy of letter in the directory Archive with the name letter.
Example 3: cp letter .. creates a copy of letter in the parent directory.
Example 4: cp ~marian/Bank.java . creates a copy of ~marian/Bank.java in your current directory
Example 5: cp -r ~marian/Wu/ch1 . copies the directory ~marian/Wu/ch1, all of its subdirectories and their contents to the current directory.
- cp dir/file1 dir/file2 creates a copy of file1 in the directory dir, with the new name file2.
- Example 5: cp letter Archive/form creates a copy of letter in the directory Archive with the name form.
Example 6: cp ~marian/Bank.java ./Cash.java creates a copy of ~marian/Bank.java in your current directory with the new name Cash.java
Example 7: cp ~marian/51/LLcode/chap02/* . creates a copy of all files in ~marian/51/LLcode/chap02 in your current directory with the new name Cash.java
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To display the date:
- date displays the current date and time.
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To find a file: (a minimal explanation)
- find dir -name 'file' -print prints to the screen all files with name file below directory dir
- Example 1: find ~tjones -name 'Bank.java' -print finds and prints the filenames of all files named Bank.java from the home directory tjones on down.
- Example 1: find . -name 'Bank*' -print finds and prints the filenames of all files beginning with the letters "Bank" from the current directory on down.
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To print a file to a Marquette MSCS printer:
- lp -dprinter file prints file on the printer .
- Example 1: lp -dstudlp1 typescript prints the file typescript on the printer studlp1 located in CU310
- Example 2: lp -dproglp1 typescript prints the file typescript on the printer proglp1 located in CU101
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To list the files in a directory:
- ls [options] dir displays a list of the files in dir
- Example 1: ls ECR displays a list of all files (and directories) in the ECR directory.
- Example 2: ls -F displays a list of all files in the current directory with directory names followed by a / and executable files followed by a *.
- Example 3: ls -a -F displays a list of all files in the current directory with directory names followed by a / and executable files followed by a * including all invisible files which begin with a period (such as .profile).
- Example 4: ls -l displays a long list of all files (and directories) in the current directory, giving information about access permissions, size of the file, when it was last modified.
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To access the online manual:
- man unix-command displays on the screen the online manual for the unix-command
- Example 1: man find displays the online information about usage of the unix command find.
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To create (make) a directory:
- mkdir dir creates a new directory called dir
- Example 1: mkdir LLcode creates a new directory called LLcode
- Example 2: mkdir chap02 chap03 creates two new directories called chap02 and chap03
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To move or rename a file :
- mv file1 file2 renames file1 with the new name file2.
- Example 1: mv Bank Bank.java renames Bank with the new name, Bank.java
- mv file1 dir moves file1 to directory dir keeping the same name.
- Example 2: mv Bank.java ECR moves Bank.java from the current directory to the directory ECR.
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To determine your current working directory:
- pwd displays the present working directory.
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To remove (delete) a file:
- rm file1 removes or deletes file1
- Example 1: rm letter deletes the file letter.
- Example 2: rm mail/letter deletes the file letter in the directory mail.
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To remove (delete) a directory:
- rm dir removes or deletes dir which must be empty.
- Example 1: rmdir letters deletes the empty directory letters.
- Example 2: rm mail/letter deletes the file letter in the directory mail.
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To connect to a remote computer over a network:
- telnet remote-computer connects to remote-computer
- Example 1: telnet studsys connects to studsys.mscs.mu.edu
- Example 2: telnet vms connects to vms.csd.mu.edu
- Example 3: quit ends a telnet session
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