How do you change the last line of a file in Unix?

How do I get the last 50 lines of a file in Unix?

head -15 /etc/passwd

To look at the last few lines of a file, use the tail command. tail works the same way as head: type tail and the filename to see the last 10 lines of that file, or type tail -number filename to see the last number lines of the file. Try using tail to look at the last five lines of your .

How do you add a new line at the end of a file in Unix?

For example, you can use the echo command to append the text to the end of the file as shown. Alternatively, you can use the printf command (do not forget to use n character to add the next line). You can also use the cat command to concatenate text from one or more files and append it to another file.

How do I remove the last line?

Now just press d twice on your keyboard. This will do exactly what you want—remove the last line. After that, press : followed by x and then press Enter .

How do you remove the last line of a file in Unix?

6 Answers

1. Use sed -i ‘$d’ <file> to edit file in place. – rambalachandran May 22 ’17 at 18:59.
2. What would be for deleting the last n lines, where n is any integer number? – Joshua Salazar Feb 18 ’19 at 20:26.
3. @JoshuaSalazar for i in {1..N}; do sed -i ‘$d’ <file>; done dont forget to replace N – ghilesZ Oct 21 ’20 at 13:23.

How do I display the first few lines of a file in Unix?

Type the following head command to display first 10 lines of a file named “bar.txt”:

1. head -10 bar.txt.
2. head -20 bar.txt.
3. sed -n 1,10p /etc/group.
4. sed -n 1,20p /etc/group.
5. awk ‘FNR <= 10’ /etc/passwd.
6. awk ‘FNR <= 20’ /etc/passwd.
7. perl -ne’1..10 and print’ /etc/passwd.
8. perl -ne’1..20 and print’ /etc/passwd.

18 дек. 2018 г.

How do I grep the last line of a file?

You can treat this as a sort of table, in which the first column is the filename and the second is the match, where the column separator is the ‘:’ character. Get last line of each file (prefixed with file name). Then, filter output based on pattern. An alternative to this could be done with awk instead of grep.

How do I add a file in Linux?

As we mentioned earlier, there is also a way append files to the end of an existing file. Type the cat command followed by the file or files you want to add to the end of an existing file. Then, type two output redirection symbols ( >> ) followed by the name of the existing file you want to add to.

How do you make a new line in terminal?

To recreate this, you’d use shift + enter after the first line to be able to create the first User object in a new line. Once at the … , a simple enter press will give you another line with the … prompt. To exit, simply hit enter at that prompt to return to the > prompt.

How do you overwrite a file in Linux?

8 Answers. The >> redirection operator will append lines to the end of the specified file, where-as the single greater than > will empty and overwrite the file.

How do I remove the first 10 lines in Unix?

Remove first N lines of a file in place in unix command line

1. Both sed -i and gawk v4.1 -i -inplace options are basically creating temp file behind the scenes. IMO sed should be the faster than tail and awk . – …
2. tail is multiple times faster for this task, than sed or awk . ( of course doesn’t fit for this question for real inplace) – thanasisp Sep 22 ’20 at 21:30.

27 июн. 2013 г.

How do I remove the last two lines in Unix?

It’s a little roundabout, but I think it’s easy to follow.

1. Count up the number of lines in the main file.
2. Subtract the number of lines you want to remove from the count.
3. Print out the number of lines you want to keep and store in a temp file.
4. Replace the main file with the temp file.
5. Remove the temp file.

19 июн. 2014 г.

How do I remove a few lines in Unix?

To Remove the lines from the source file itself, use the -i option with sed command. If you dont wish to delete the lines from the original source file you can redirect the output of the sed command to another file.

How do I remove the last 10 lines in Unix?

Remove the Last N Lines of a File in Linux

1. awk.
2. head.
3. sed.
4. tac.
5. wc.

8 нояб. 2020 г.

How do I remove the first line in Unix?

To delete a charecter in a line

1. Delete First two charters in lin sed ‘s/^..//’ file.
2. Delete last two chrecters in line sed ‘s/..$//’ file.
3. Delete blank line sed ‘/^$/d’ file.

How do you delete the first and last line in Unix?

How it works :

1. -i option edit the file itself. You could also remove that option and redirect the output to a new file or another command if you want.
2. 1d deletes the first line ( 1 to only act on the first line, d to delete it)
3. $d deletes the last line ( $ to only act on the last line, d to delete it)

11 июн. 2015 г.