Posted by For part 1 of Unix/ Linux commands which includes file commands and process commands. Click here.
SYSTEM COMMANDS:
| COMMAND | DESCRIPTION |
|---|---|
| shutdown | Shuts down the machine. |
| reboot | Restart the machine. |
| df | Displays disk usage. |
| du |
Displays directory space usage. |
| free |
Displays memory and swap usage. |
| finger user |
Displays info about user. |
| date |
Displays current date and time. |
FILTER COMMANDS:
| COMMAND | DESCRIPTION |
|---|---|
|
find [starting_dir] -name “pattern” -print |
Starts searching from the starting_dir for the name of the file(s) matching the pattern and prints it on the standard output. |
|
find [starting_directory] – type [f|d] -print |
Starts searching from the starting_directory for the file type: f=plain text, d=directory and prints it on the standard output. |
|
find [starting_dir] -name “pattern” -exec ls -l {}\; |
Starts searching from the starting_dir for the name of the file matching the pattern and executes the next command to display a long list of the files. |
|
sort filename |
Sorts the contents of a text file named as filename, line by line |
|
sort -r filename |
Reverse sort the contents of a text file named as filename, line by line (-r reverse) |
|
sort -o output.txt file.txt |
Sorts file.txt and stores the result in output.txt (-o output) |
|
sort -c filename |
To check if file named as filename is already sorted (-c check) |
|
sort -n filename |
To sort a file named as filename numerically (-n numeric sort) |
| wc filename | Counts the words, newlines, or bytes of each input file named as filename |
|
wc -l filename |
Prints the newline counts on the standard output. (-l lines) |
| wc -m filename |
Prints the character counts on the standard output. (-m chars) |
| wc -c filename | Prints the byte counts on the standard output. (-c bytes) |
| wc -w filename | Prints the word counts on the standard output. (-w words) |
|
split filename |
Splits the file named as filename into multiple files with 1000 lines into each output file by default. |
| split {filename} {prefix_name} | Splits the file named as filename and Creates split files with specified prefix_name. |
|
split -l number_of_lines filename |
Splits the file named as filename with the specified number of lines per output file. |
|
cut -d “delimiter” filename |
cuts the file named as filename by the delimiter. |
|
paste filename |
Displays the contents of file named as filename |
|
paste file1 file2 |
By default, the paste command merges the files (file1,file2) in parallel. The paste command writes corresponding lines from the files as a tab delimited on the standard output. |
|
uniq filename |
Reports or filters out repeated lines in a file named as filename |
|
uniq -c filename |
Prefix lines with a number representing how many times they occurred. (-c count) |
|
uniq -d filename |
Displays only duplicated lines of the file on the standard output (-d repeated/duplicated) |
|
nl filename |
To number each line in the file and display the result to standard output. |
FILE COMPARISON COMMANDS:
| COMMAND | DESCRIPTION |
|---|---|
|
cmp file1 file2 |
If two files are different and where the first difference appears. |
|
comm file1 file2 |
Display the differences in text files in a different format |
|
diff file1 file2 |
Analyzes file1 and file2 and prints the lines that are different on the standard output. |
|
diff -i file1 file2 |
Ignores the case(upper case or lower case) differences in file contents. |
|
diff -y file1 file2 |
To display the differences between the files in a side by side view. |
|
diff -b file1 file2 |
Ignore white space differences. |
|
diff -B file1 file2 |
Ignore blank lines |
