What command will print all lines with exactly two characters?

By default, grep prints the matching lines. In addition, two variant programs egrep and fgrep are available. Egrep is the same as grep -E.

How do I grep a line starting with numbers?

4 Answers. ^[[:space:]]*$i:[0-9][0-9]:[0-9][0-9] this will tell egrep to match from start of line. if the line starts with a whitespace at the start of line or just starts with your pattern grep will match it. Also this will tell grep to match not to match greedily.

How do I print a specific line using grep?

To print a specific number of lines after matching lines, use the -A ( or –after-context ) option.

Which grep command line switch means not?

Grep NOT using grep -v. Using grep -v you can simulate the NOT conditions. -v option is for invert match. i.e It matches all the lines except the given pattern.

How do you grep before and after lines?

To also show you the lines before your matches, you can add -B to your grep. The -B 4 tells grep to also show the 4 lines before the match. Alternatively, to show the log lines that match after the keyword, use the -A parameter. In this example, it will tell grep to also show the 2 lines after the match.

How do I print every 2 lines in a SED file?

Print every 2 lines: $ sed ‘n;n;N;d’ file AIX Solaris HPUX n;n; => This command prints 2 lines and the 3rd line is present in the pattern space. N command reads the next line and joins with the current line, and d deltes the entire stuff present in the pattern space.

What is global regular expression print (grep)?

Grep is an acronym that stands for Global Regular Expression Print. Grep is a Linux / Unix command line tool used to search for a string of characters in a specified file. The text search pattern is called a regular expression. When it finds a match, it prints the line with the result.

How do I Grep a string in a file in Linux?

1. Search for the given string in a single file. The basic usage of grep command is to search for a specific string in the specified file as shown below. Syntax: grep “literal_string” filename. $ grep “this” demo_file this line is the 1st lower case line in this file. Two lines above this line is empty.

How to use grep -E option for extended regexp?

grep -E option is for extended regexp. If you use the grep command with -E option, you just need to use | to separate multiple patterns for the or condition. For example, grep either Tech or Sales from the employee.txt file. Just use the | to separate multiple OR patterns.