9-2 How do you copy/move/rename/remove files? How do you create a directory ? What is redirection and piping? Readings: See CCSO’s Unix pages andCCSO’s Unix pages

9-3 cp option file1 file2 First Version This is one version of the cp command. file2 is created and the contents of file1 are copied into file2. If file2 already exits, it will be replaced with a new one. where option is -i Protects you from overwriting an existing file by asking you for a yes or no before it copies a file with an existing name. -r Can be used to copy directories and all their contents into a new directory

9-4 cp file1 file2 file3 … dirname Second Version This version copies the files file1, file2, file3,… into the directory dirname.

9-5 Copy the file named mp1_data.m from the cs101/data directory into the pwd. cs101 data > cp ~cs101/data/mp1_data.m. {FILES: mp1_data.m, mp1.m } jsmith mp1 pwd The (.) dot means “here”, that is, your pwd.

9-6 Copy the file named mp1_data.m from the cs101/data directory into the mp1 directory. cs101 data > cp ~cs101/data/mp1_data.m mp1 {FILES: mp1_data.m, mp1.m } jsmith mp1 pwd The (.) dot means “here”, that is, your pwd.

9-7 Example: To create a new directory named “ temp ” and to copy the contents of an existing directory named mp1 into temp, > cp -r mp1 temp This is useful to make a backup copy of your mp1 files.

9-8 mv option file1 file2 First Version This is one version of the mv command. file1 is renamed file2. where option is -i Protects you from overwriting an existing file by asking you for a yes or no before it copies a file with an existing name.

9-9 mv dirname1 dirname2 Second Version In this version dirname1 is renamed dirname2

9-10 mv file1 file2 file3 … dirname Third Version The files file1, file2, file3,… are moved into the directory dirname.

9-11 Move all the files with.c suffix from the temp directory to the mp2 directory. jsmith temp > mv temp/*.c mp2 {FILES: mp2.c, mp2.h } source mp2 pwd Move the input.dat file into the home directory. > mv source/input.dat. {FILES: stat.c, input.dat }{FILES: edit.c }

9-12 rm option file1 file2 file3 … The rm command removes (deletes) each file in the list. where option is -i For each file in the list, the user is asked whether or not to delete. -r Deletes a directory and every file or directory in it. Example: To delete a directory named temp and all its contents, > rm -r temp Where temp is a subdirectory of the present working directory. Be very careful in using this command!!!

9-13 mkdir dirname The mkdir command makes a subdirectory named dirname in the present working directory. Lab assignment: Create a directory named lab2 as a subdirectory of your home directory. Assuming that you are in your home directory, type > mkdir lab2 The mkdir creates a new directory but it does not cd for you.

9-14 Find all files named mp2.c. jsmith mp2 > find -name “mp2.c” -type f {FILES: mp2.c, main.c } workspace mp2 pwd {FILES: mp2.c, main.c } Find all directories named mp2. > find -name “mp2” -type d

9-15 You want to your lab TA and send him/her all your files in the mp2 directory. > tar -czvf blah.tar.gz * creates a file named blah.tar.gz mp2 pwd {FILES: mp2.c, input.c, stat.c, mp2.h, … } When your TA receives this file he/she can extract its contents by typing: > tar -xzvf blah.tar.gz

9-16 Links commands to commands. Pipes are used to direct the output of one command to the input of the second. Unix uses the vertical bar “ | ” symbol to perform piping. General form > command1 | command2

Example: when you use the ls command to list the contents of a directory the output may not fit on one full terminal screen. Since the screen scrolls you may not see the first part of the output. Use a pipe to solve this problem > ls -la | more

9-18 Links commands to a file. Redirection is used to take information that would normally be seen on the screen and funnels it to a file or vice versa. Unix uses the “ > ” or “ < “ symbols to perform redirection. General form > command > filename output redirected to file filename > command < filename input from file filename not keyboard

9-19 Example: you can send the output from the ls command to a file” screen.txt ”. You can then use gedit to edit the file. > ls -la > screen.txt

9-20 passwd - change your password clear - clears the terminal screen leaving the prompt > whoami - identity of the user man command - manual of information concerning command for example, type in “ man finger” to find all the options available for this command.

9-21 alias abbreviation command provides an alias for a command. For example, if you type, > alias dir ls -la then dir is an alias for ls -la so if you type, > dir this is the same as typing in > ls -la To make this change effective each time you login, gedit the.cshrc file and type in the alias command. When you add a line at the end of the.cshrc file terminate the line by typing.

9-22 alias abbreviation ‘ command1 command2 ’ provides an alias for compound commands For example, if you type, > alias dir ‘ls -la | more’ then dir is an alias for ls -la | more so if you type, > dir this is the same as typing > ls -la | more and this command displays the contents of the pwd one screen at a time.

9-23 alias abbreviation ‘ command1 \!* command2 ’ provides an alias for compound commands and passes an argument. For example, if you type, > alias dir ‘ls -la \!* | more’ then > dir lab1 is the same as typing in > ls -la lab1 | more and this command displays the contents of the subdirectory of the pwd named lab1, one screen at a time.

9-24 How to: copy- cp/move - mv/rename - mv/remove-rm files. Use the mkdir command to create a directory. Redirection - uses the “ ” symbol. By default, most commands expect input data from the keyboard and output data goes to the monitor. Using redirection symbols, you can specify that the input comes from a file and output goes to a file. Piping - uses the “ | ” symbol. Output data from one command can be piped as into to another command.