How do you grep a line after a match?

How do you grep a line after a match?

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 a specific line in awk?

Write a bash script to print a particular line from a file

1. awk : $>awk ‘{if(NR==LINE_NUMBER) print $0}’ file.txt.
2. sed : $>sed -n LINE_NUMBERp file.txt.
3. head : $>head -n LINE_NUMBER file.txt | tail -n + LINE_NUMBER Here LINE_NUMBER is, which line number you want to print. Examples: Print a line from single file.

How do I remove text after a specific character in Linux?

In Bash (and ksh, zsh, dash, etc.), you can use parameter expansion with \% which will remove characters from the end of the string or # which will remove characters from the beginning of the string. If you use a single one of those characters, the smallest matching string will be removed.

How do you display the first line of a text file in Unix?

To look at the first few lines of a file, type head filename, where filename is the name of the file you want to look at, and then press . By default, head shows you the first 10 lines of a file. You can change this by typing head -number filename, where number is the number of lines you want to see.

How do you grep 3 lines before and after?

For BSD or GNU grep you can use -B num to set how many lines before the match and -A num for the number of lines after the match. If you want the same number of lines before and after you can use -C num . This will show 3 lines before and 3 lines after.

How do I trim a string in Linux?

Example-2: Trim string data using `sed` command `sed` command is another option to remove leading and trailing space or character from the string data. The following commands will remove the spaces from the variable, $myVar using `sed` command. Use sed ‘s/^ *//g’, to remove the leading white spaces.

How do you trim a string in Linux?

cut command in Linux with examples

1. -b(byte): To extract the specific bytes, you need to follow -b option with the list of byte numbers separated by comma.
2. -c (column): To cut by character use the -c option.
3. -f (field): -c option is useful for fixed-length lines.

How do you grep only one line?

When searching for a string, grep will display all lines where the string is embedded in larger strings. To return only those lines where the specified string is a whole word (enclosed by non-word characters), use the -w ( or –word-regexp ) option.

How do you use an escape character in an AWK statement?

Use Awk with () Escape Character It allows you to take the character following it as a literal that is to say consider it just as it is. In the example below, the first command prints out all line in the file, the second command prints out nothing because I want to match a line that has $25.00, but no escape character is used.

What is the default line type in AWK?

The default is a newline character. print automatically outputs the contents of ORS at the end of whatever it is given to print. In the above example, the awk command with NR prints all the lines along with the line number.

How do I Grep a specific line in a file?

Beginning at the first line in the file, grep copies a line into a buffer, compares it against the search string, and if the comparison passes, prints the line to the screen. Grep will repeat this process until the file runs out of lines.

How does grep work in Linux?

In the simplest terms, grep (global regular expression print) will search input files for a search string, and print the lines that match it. Beginning at the first line in the file, grep copies a line into a buffer, compares it against the search string, and if the comparison passes, prints the line to the screen.