How do I truncate a text file?

How do I truncate a text file?

The easiest and most used method to truncate files is to use the > shell redirection operator. Let’s break down the command: The : colon means true and produces no output. The redirection operator > redirect the output of the preceding command to the given file.

How do I get top 10 files in Unix?

How to find out top Directories and files in Linux

1. du command -h option : display sizes in human readable format (e.g., 1K, 234M, 2G).
2. du command -s option : show only a total for each argument (summary).
3. du command -x option : skip directories on different file systems.

How do I truncate a file in bash?

Using Truncate Command: By running the bash command, the output will be as same as in the image. After that, we will use the “truncate” command followed by the “-s” keyword. This keyword “-s” is followed by the number “0”, which means that this file will be truncated to zero contents.

How do I get top 10 files in Linux?

Command To Find Top 10 Largest Files In Linux

1. du command -h option : display file sizes in human readable format, in Kilobytes, Megabytes and Gigabytes.
2. du command -s option : Show total for each argument.
3. du command -x option : Skip directories.
4. sort command -r option : Reverse the result of comparisons.

How do I find the first 10 files 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.

How to limit the number of lines in a file?

50001,$ means the lines from 50001 to the end. You can make a backup of the file by adding an extension argument to -i, for example, .backup or .bak: In OS-X or FreeBSD you must provide an argument to -i – so to do this while avoiding making a backup: The long argument name version is as follows, with and without the backup argument:

How to read a small number of lines in Bash?

For a small number of lines, you can use the read built-in. If you want to read all lines, you can put them in an array (ksh/bash/zsh only). If you want to make this reusable code, put it in a function. # Read at most MAX input lines (default: all) into the VAR array (default: $ {lines [@]}).

How to print nth line of text in Linux?

Below are the two better ways to print nth line of text files in linux. One of the easiest way of printing nth line of a text file is by using the combination of head and tail command.Below is an exapmle of how to use it for displaying the 9th line of a file named sample.txt

How to access nth line number of standard output?

Use head and tail, e.g. accessing the 2nd line of an output: If being short to type is paramount and the file isn’t very large: If the file is long and you’re only interested in one line, use sed to print the desired line and quit, or tail to remove the previous lines and head to extract the first line of the result.