grep Flashcards
What does the -i option do in grep?
The -i option makes the search case-insensitive. For example, ‘grep -i error file.txt’ matches ‘error’, ‘Error’, and ‘ERROR’.
What does the -v option do in grep?
The -v option inverts the match, displaying lines that do NOT match the pattern. For example, ‘grep -v DEBUG file.txt’ excludes lines containing ‘DEBUG’.
What does the -c option do in grep?
The -c option counts the number of matching lines instead of displaying them. For example, ‘grep -c keyword file.txt’ outputs the number of lines containing ‘keyword’.
What does the -n option do in grep?
The -n option displays line numbers alongside matching lines. For example, ‘grep -n "pattern" file.txt’ shows matching lines with their line numbers.
What does the -l option do in grep?
The -l option lists only the names of files containing matches. For example, ‘grep -l "error" *.log’ lists log files containing ‘error’.
What does the -L option do in grep?
The -L option lists only the names of files that do NOT contain any matches. For example, ‘grep -L "keyword" *.txt’ lists files that do not contain ‘keyword’.
What does the -r option do in grep?
The -r option enables recursive search through directories. For example, ‘grep -r "keyword" /project’ searches all files in the /project directory and subdirectories.
What does the -w option do in grep?
The -w option matches whole words only. For example, ‘grep -w "cat" file.txt’ matches ‘cat’ as a whole word but not ‘category’.
What does the -A option do in grep?
The -A option displays ‘n’ lines after each match. For example, ‘grep -A 3 "error" file.log’ shows the matching lines and 3 lines after each match.
What does the -B option do in grep?
The -B option displays ‘n’ lines before each match. For example, ‘grep -B 2 "404" file.log’ shows 2 lines before each matching line.
What does the -C option do in grep?
The -C option displays ‘n’ lines of context before and after each match. For example, ‘grep -C 1 "failed" file.log’ shows 1 line before and 1 line after each match.
What does the -e option do in grep?
The -e option allows specifying multiple patterns. For example, ‘grep -e "pattern1" -e "pattern2" file.txt’ matches lines containing ‘pattern1’ or ‘pattern2’.
What does the -f option do in grep?
The -f option allows reading patterns from a file. For example, ‘grep -f patterns.txt file1.txt’ matches lines containing patterns listed in patterns.txt.
What does the –color option do in grep?
The –color option highlights matching text in the output. For example, ‘grep –color "keyword" file.txt’ highlights ‘keyword’ in the results.
What does the -q option do in grep?
The -q option runs grep quietly, suppressing all output. For example, ‘grep -q "ERROR" file.txt && echo "Error found"’ outputs ‘Error found’ if ‘ERROR’ exists.
What does the grep command ‘grep -i "error" /var/log/syslog’ do?
It performs a case-insensitive search for the word ‘error’ in the /var/log/syslog file and displays all matching lines.
What does the grep command ‘grep -v "debug" /var/log/messages’ do?
It displays all lines from /var/log/messages that do not contain the word ‘debug’.
What does the grep command ‘grep -c "timeout" application.log’ do?
It counts the number of lines in application.log that contain the word ‘timeout’.
What does the grep command ‘grep -n "keyword" notes.txt’ do?
It searches for the word ‘keyword’ in notes.txt and displays the matching lines along with their line numbers.
What does the grep command ‘grep -l "failure" /var/log/*.log’ do?
It lists the names of log files in /var/log that contain the word ‘failure’.
What does the grep command ‘grep -L "success" results.txt’ do?
It lists the names of files that do not contain the word ‘success’ in results.txt.
What does the grep command ‘grep -r -i "critical" /etc’ do?
It recursively searches for the word ‘critical’ in all files under the /etc directory, case-insensitively.
What does the grep command ‘grep -w "error" /var/log/syslog’ do?
It searches for whole-word occurrences of ‘error’ in /var/log/syslog and excludes matches where ‘error’ is part of another word.
What does the grep command ‘grep -A 2 "failed" logs.txt’ do?
It searches for lines containing ‘failed’ in logs.txt and displays each matching line along with the 2 lines after it.
What does the grep command ‘grep -B 3 "denied" auth.log’ do?
It searches for lines containing ‘denied’ in auth.log and displays each matching line along with the 3 lines before it.
What does the grep command ‘grep -C 3 "password" server.log’ do?
It searches for lines containing ‘password’ in server.log and displays each matching line along with 3 lines of context before and after the match.
What does the grep command ‘grep -f patterns.txt -i /var/log/syslog’ do?
It reads patterns from patterns.txt and performs a case-insensitive search for those patterns in the /var/log/syslog file.
What does the grep command ‘grep –color -n "login" access.log’ do?
It searches for the word ‘login’ in access.log, displays matching lines with their line numbers, and highlights the matches in color.
What does the grep command ‘grep -q "error" application.log && echo "Error found"’ do?
It performs a quiet search for ‘error’ in application.log. If a match is found, it outputs ‘Error found’.
What does the grep command ‘grep -r -l "connection lost" /var/log/’ do?
It recursively searches for ‘connection lost’ in all files under /var/log and lists the names of the files containing the match.
What does the -d option do in the cut command?
The -d option specifies the delimiter used to separate fields. For example, ‘cut -d , -f 1 file.csv’ extracts the first field from a CSV file.
What does the -f option do in the cut command?
The -f option selects which fields to display from a delimited file. For example, ‘cut -f 2 file.txt’ displays the second field from a tab-delimited file.
What does the -c option do in the cut command?
The -c option selects specific characters from a line. For example, ‘cut -c 1-5 file.txt’ displays the first 5 characters of each line in file.txt.
What does the -b option do in the cut command?
The -b option selects specific bytes from a line. For example, ‘cut -b 1-4 file.txt’ displays the first 4 bytes of each line in file.txt.
What does the -d option do in the sort command?
The -d option sorts input data by considering only alphanumeric characters, ignoring non-alphanumeric characters. For example, ‘sort -d file.txt’ sorts the file with alphanumeric sorting.
What does the -n option do in the sort command?
The -n option sorts the input numerically. For example, ‘sort -n numbers.txt’ sorts the lines of numbers.txt in ascending numerical order.
What does the -r option do in the sort command?
The -r option reverses the order of the sort. For example, ‘sort -r file.txt’ sorts the contents of file.txt in descending order.
What does the -u option do in the sort command?
The -u option removes duplicate lines from the sorted output. For example, ‘sort -u file.txt’ sorts file.txt and removes any duplicate lines.
What does the -k option do in the sort command?
The -k option allows sorting by specific fields. For example, ‘sort -k 2 file.txt’ sorts file.txt based on the second field of each line.
What does the -t option do in the sort command?
The -t option specifies the delimiter for sorting fields. For example, ‘sort -t , -k 2 file.csv’ sorts the file by the second field in CSV format.
What does the –version option do in the sort command?
The –version option displays the version of the sort command. For example, ‘sort –version’ outputs the version information for the sort utility.
What does the –check option do in the sort command?
The –check option checks if the input is already sorted without sorting it. For example, ‘sort –check file.txt’ returns an error if the file is not sorted.
What does the -f option do in the sort command?
The -f option ignores case when sorting. For example, ‘sort -f file.txt’ sorts file.txt in a case-insensitive manner.
What does the -b option do in the sort command?
The -b option ignores leading spaces when sorting. For example, ‘sort -b file.txt’ will sort the lines of file.txt while ignoring any leading whitespace.
What does the -M option do in the sort command?
The -M option sorts by month names. For example, ‘sort -M months.txt’ sorts months.txt by the month names (e.g., Jan, Feb, Mar).
What does the -z option do in the sort command?
The -z option sets the input and output to be delimited by null characters instead of newlines. For example, ‘sort -z file.txt’ treats nulls as delimiters in file.txt.
cut -d , -f 1 employees.csv
This command extracts the first column from a comma-separated CSV file named employees.csv.
cut -d : -f 2 password_file.txt
This command extracts the second field (usually the password) from a colon-separated file such as a password file.
cut -f 1-3 data.txt
This command extracts the first three fields from a tab-delimited text file named data.txt.
cut -c 1-5 log.txt
This command extracts the first five characters from each line in log.txt.
cut -b 1-4 report.txt
This command extracts the first 4 bytes from each line of report.txt.
sort -d names.txt
This command sorts the lines of names.txt alphabetically, considering only alphanumeric characters.
sort -n numbers.txt
This command sorts the contents of numbers.txt numerically, from lowest to highest.
sort -r reverse.txt
This command sorts the contents of reverse.txt in reverse (descending) order.
sort -u list.txt
This command sorts list.txt and removes any duplicate lines.
sort -k 2 people.txt
This command sorts people.txt based on the second field (e.g., last names).
sort -t , -k 3 data.csv
This command sorts data.csv by the third field using a comma as the delimiter.
sort -f names.txt
This command sorts names.txt in a case-insensitive manner.
sort -b input.txt
This command sorts input.txt while ignoring leading spaces.
sort -M months.txt
This command sorts the months.txt file containing month names in chronological order.
sort -z file.txt
This command sorts file.txt where records are separated by null characters instead of newlines.
