1.ls
List directory contents.
- List files one per line:
ls -1
- List all files, including hidden files:
ls -a
- Long format list (permissions, ownership, size and modification date) of all files:
ls -la
- Long format list with size displayed using human readable units (KB, MB, GB):
ls -lh
- Long format list sorted by size (descending):
ls -lS
- Long format list of all files, sorted by modification date (oldest first):
ls -ltr
2.cat
Print and concatenate files.
- Print the contents of a file to the standard output:
cat file
- Concatenate several files into the target file:
cat file1 file2 > target_file
- Append several files into the target file:
cat file1 file2 >> target_file
- Number all output lines:
cat -n file
3. mv
Move or rename files and directories.
- Move files in arbitrary locations:
mv source target
- Do not prompt for confirmation before overwriting existing files:
mv -f source target
- Do not prompt for confirmation before overwriting existing files but write to standard error before overriding:
mv -fi source target
- Move files in verbose mode, showing files after they are moved:
mv -v source target
4. touch
Change a file access and modification times (atime, mtime).
- Create a new empty file(s) or change the times for existing file(s) to current time:
touch filename
- Set the times on a file to a specific date and time:
touch -t YYYYMMDDHHMM.SS filename
- Use the times from a file to set the times on a second file:
touch -r filename filename2
