cat file1.txt file2.txt > target.txt<\/pre>Combines the contents of file1.txt<\/code> and file2.txt<\/code> into target.txt<\/code>, allowing you to merge multiple files into a single output file.<\/p>15. grep command<\/h2>
The grep<\/code> command<\/a> searches for specific patterns or keywords within files or command output.<\/p>Syntax:<\/p>
grep [options] keyword [file]<\/pre>Common options:
• -i<\/code> → performs a case-insensitive search
• -r<\/code> → searches recursively through directories
• -n<\/code> → displays line numbers with matching results<\/p>Example:<\/p>
ls | grep \"file.txt\"<\/pre>Filters the output of the ls<\/code> command to show only entries that match file.txt<\/code>, allowing you to quickly locate specific items in a list.<\/p>16. sed command<\/h2>
The sed<\/code> command<\/a> searches, replaces, and transforms text within files or input streams.<\/p>Syntax:<\/p>
sed [options] 's\/pattern\/replacement\/' file<\/pre>Common options:
• -i<\/code> → edits files in place without creating a new output
• -n<\/code> → suppresses automatic output (used with explicit print commands)
• -e<\/code> → allows multiple editing expressions<\/p>Example:<\/p>
sed 's\/red\/blue\/' colors.txt<\/pre>Replaces the first occurrence of red<\/code> with blue<\/code> in each line of colors.txt<\/code>, allowing quick text modifications without opening a file manually.<\/p>17. head command<\/h2>
The head<\/code> command displays the first lines or bytes of a file or command output.<\/p>Syntax:<\/p>
head [options] file_name<\/pre>Common options:
• -n<\/code> → specifies the number of lines to display
• -c<\/code> → specifies the number of bytes to display<\/p>Example:<\/p>
head -n 5 file.txt<\/pre>Displays the first five lines of file.txt<\/code>, allowing you to quickly preview the beginning of a file without opening it fully.<\/p>18. tail command<\/h2>
The tail<\/code> command<\/a> displays the last lines or bytes of a file or command output.<\/p>Syntax:<\/p>
tail [options] file_name<\/pre>Common options:
• -n<\/code> → specifies the number of lines to display
• -c<\/code> → specifies the number of bytes to display
• -f<\/code> → follows the file in real time as new lines are added<\/p>Example:<\/p>
ping -c 10 8.8.8.8 | tail -n 5<\/pre>Displays the last five lines of the ping<\/code> command output, allowing you to focus on the most recent results or summaries.<\/p>19. awk command<\/h2>
The awk<\/code> command<\/a> processes and analyzes text by applying patterns and actions to structured data.<\/p>Syntax:<\/p>
awk 'pattern {action}' input_file<\/pre>Common options:
• -F<\/code> → specifies a custom field separator
• -v<\/code> → assigns variables for use within the command
• -f<\/code> → reads the awk<\/code> program from a file<\/p>Example:<\/p>
awk -F':' '{ total += $2; students[$1] = $2 } END { average = total \/ length(students); for (student in students) if (students[student] > average) print student }' score.txt<\/pre>Calculates the average value from score.txt<\/code> and prints the names of entries with values above the average, allowing you to perform data analysis directly in the terminal.<\/p>20. sort command<\/h2>
The sort<\/code> command arranges lines of text in a file or input stream in a specified order.<\/p>Syntax:<\/p>
sort [options] [file_name]<\/pre>Common options:
• -r<\/code> → sorts in reverse order
• -n<\/code> → sorts numerically instead of alphabetically
• -k<\/code> → sorts based on a specific column or field<\/p>Example:<\/p>
sort -n file.txt<\/pre>Sorts the contents of file.txt<\/code> numerically and prints the result to the terminal without modifying the original file.<\/p>21. cut command<\/h2>
The cut<\/code> command<\/a> extracts specific sections of text from each line of a file or input stream.<\/p>Syntax:<\/p>
cut [options] file<\/pre>Common options:
• -f<\/code> → selects specific fields (columns)
• -d<\/code> → specifies a delimiter to separate fields
• -c<\/code> → extracts specific character positions
• -b<\/code> → extracts specific byte ranges<\/p>Example:<\/p>
cut -d',' -f3-5 list.txt<\/pre>Extracts the third to fifth fields from each line in list.txt<\/code> using a comma as the delimiter, allowing you to isolate structured data from files like CSVs.<\/p>22. diff command<\/h2>
The diff<\/code> command compares two files and displays the differences between them.<\/p>Syntax:<\/p>
diff [options] file_name1 file_name2<\/pre>Common options:
• -c<\/code> → displays differences in context format with surrounding lines
• -u<\/code> → shows unified output format (commonly used for patches)
![\"\"](\"https:\/\/imagedelivery.net\/LqiWLm-3MGbYHtFuUbcBtA\/wp-content\/uploads\/sites\/2\/2023\/02\/VPS-hosting-banner.png\/public\")
<\/a><\/figure>