Creating a File
Command |
Effect |
cat > myfile |
Allows you to enter text with the keyboard to be stored in the file named myfile. After entering the desired text, press Crtl-D. |
vi myfile |
Launches the vi text editor, given a file name of myfile. |
Creating a Directory
Command |
Effect |
mkdir dir2 |
Creates a directory (within the current directory) named dir2. |
Displaying File Contents
Command |
Effect |
cat myfile |
Displays the entire contents of the file name myfile. |
more myfile |
Displays the contents of the file myfile one page (screen-full) at a time. |
Comparing Files
Command |
Effect |
diff file1 file2 |
Performs a line-by-line comparison of the files file1 and file2. The differences are displayed in the shell window. |
cmp file1 file2 |
Performs a byte-by-byte comparison of the files file1 and file2. The differences are displayed in the shell window. |
Changing Access Modes
Command |
Effect |
chmod mode file1 file2 |
Changes the modes of both files file1 and file2 to mode. |
chmod -R mode dir |
Changes the modes of all files and directories within the dir directory to mode. |
Here are the mode settings:
- Users affected
- u: user (owner)
- g: group
- o: other (world)
- Actions
- +: add permission
- -: remove permission
- Access types
- r: read
- w: write
- x: execute
For example:
UNIX> chmod go-rwx foo.c
removes read, write and execute permissions for "group" and "other" users for the file foo.c.
Listing Files and Directories
Command |
Effect |
ls |
Lists the contents of the current (working) directory. |
ls -a |
Lists the contents of the current directory, including dotfiles. |
ls -l |
Lists the contents of the current directory in long format (shows access modes). |
Moving (or Renaming) Files and Directories
Command |
Effect |
mv src-file dest-file |
Renames the file src-file to dest-file |
mv src-file dest-dir |
Moves the file src-file into the dest-dir directory. |
mv src-diri dest-dir |
Renames the src-dir directory to dest-dir; alternatively, if dest-dir already exists, moves the src-dir directory into the dest-dir directory. |
mv -i src dest |
Moves src to dest, but prompts before overwriting existing files/directories. |
Copying Files
Command |
Effect |
cp src-file dest-file |
Makes a copy of the file src-file and names the copy dest-file. |
cp src-file dest-dir |
Copies the file src-file into the dest-dir directory. |
cp -R src-dir dest-dir |
Copies the src-dir directory and all of its contents into the dest-dir directory. |
cp -i src dest |
Copies src into dest, but prompts before overwriting existing files. |
Deleting Files and Directories
Command |
Effect |
rm myfile |
Deletes (removes) the file myfile. |
rmdir mydir |
Deletes the empty directory named mydir. |
rm -r mydir |
Deletes the mydir directory and all of its contents. |
rm -i myfile |
Deletes the file myfile, but prompts before doing so. |
Compressing Files
Command |
Effect |
gzip myfile |
Compresses the file myfile, replacing it with the file named myfile.gz. |
gunzip myfile.gz |
Uncompresses the file myfile.gz, replacing it with the file named myfile. |
Changing the Working Directory
Command |
Effect |
cd |
Changes the current (working) directory to your login (home) directory. |
cd mydir |
Changes to the mydir directory. |
Displaying the Name of the Current Directory
Command |
Effect |
pwd |
Displays the absolute path of the current (working) directory. |
Searching Within Files
Command |
Effect |
grep hello myfile |
Displays the lines within the file myfile that contain the string hello. |
grep hello file1 file2 ... |
Displays the lines within files file1, file2, etc. that contain the string hello. |
grep hello * |
Displays the lines within any file in the current directory that contain the string hello. |
grep -v hello * |
Displays the lines within any file in the current directory that do not contain the string hello. |
grep -i hello * |
Displays the lines within any file in the current directory that contains the string hello in any letter-case. For example, lines containing "Hello", "HELLO" and "HeLlO" would be displayed. |