How do I display a specific line in a file in Linux?
How to Display Specific Lines of a File in Linux Command Line
- Display specific lines using head and tail commands. Print a single specific line. Print specific range of lines.
- Use SED to display specific lines.
- Use AWK to print specific lines from a file.
How do I print the first line of a file in Linux?
head command example to print first 10/20 lines
- head -10 bar.txt.
- head -20 bar.txt.
- sed -n 1,10p /etc/group.
- sed -n 1,20p /etc/group.
- awk ‘FNR <= 10’ /etc/passwd.
- awk ‘FNR <= 20’ /etc/passwd.
- perl -ne’1..10 and print’ /etc/passwd.
- perl -ne’1..20 and print’ /etc/passwd.
How do I extract a specific line from a file in Unix?
To extract a range of lines, say lines 2 to 4, you can execute either of the following:
- $ sed -n 2,4p somefile. txt.
- $ sed ‘2,4! d’ somefile. txt.
How do I print a specific line using sed?
In this article of sed series, we will see how to print a particular line using the print(p) command of sed. Similarly, to print a particular line, put the line number before ‘p’. $ indicates the last line. !
How do you display the nth line of a file in Unix?
Below are three great ways to get the nth line of a file in Linux.
- head / tail. Simply using the combination of the head and tail commands is probably the easiest approach. …
- sed. There are a couple of nice ways to do this with sed . …
- awk. awk has a built in variable NR that keeps track of file/stream row numbers.
How do I grep a file in Linux?
How to use the grep command in Linux
- Grep Command Syntax: grep [options] PATTERN [FILE…] …
- Examples of using ‘grep’
- grep foo /file/name. …
- grep -i “foo” /file/name. …
- grep ‘error 123’ /file/name. …
- grep -r “192.168.1.5” /etc/ …
- grep -w “foo” /file/name. …
- egrep -w ‘word1|word2’ /file/name.
How do I print the first line of a file?
To store the line itself, use the var=$(command) syntax. In this case, line=$(awk ‘NR==1 {print; exit}’ file) . With the equivalent line=$(sed -n ‘1p’ file) . will be marginally faster as read is a built-in bash command.
How do I read the first line of a file?
Use file. readline() to read a single line from a file
Call file. readline() to get the first line of the file and store this in a variable first_line . Create a second variable, last_line , and iterate through all lines in the file until the end.
How do I copy a line from one file to another in Linux?
You can use grep to search for a regular expression in details. txt and redirect the result to the new file. If not you will have to search for each line you want to copy, still using grep, and append them to new. txt using >> in stead of > .
How do you find the first two lines of a 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 <Enter>. 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.
What is the use of awk in Linux?
Awk is a utility that enables a programmer to write tiny but effective programs in the form of statements that define text patterns that are to be searched for in each line of a document and the action that is to be taken when a match is found within a line. Awk is mostly used for pattern scanning and processing.
How do I print a specific line of a file?
Write a bash script to print a particular line from a file
- awk : $>awk ‘{if(NR==LINE_NUMBER) print $0}’ file.txt.
- sed : $>sed -n LINE_NUMBERp file.txt.
- 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.
What command will print all lines in the file?
Printing Lines from a File using sed
sed “p” command lets us print specific lines based on the line number or regex provided. sed with option -n will suppress automatic printing of pattern buffer/space.
How do I grep a specific line number?
The -n ( or –line-number ) option tells grep to show the line number of the lines containing a string that matches a pattern. When this option is used, grep prints the matches to standard output prefixed with the line number.