Printing a File with Line Skipping in Bash

In Bash, there are several ways to print a file while skipping a specified number of lines from the beginning. This can be particularly useful when dealing with large files and you’re only interested in a portion of the content.

Using tail Command

The tail command is primarily used to display the last part of a file, but it also has an option to start displaying from a specified line number. To skip the first X lines of a file, you can use the -n +X option with tail, where X+1 is the starting line number.

For example, if you want to print a file named huge-file.log skipping the first 10 lines, you would use:

tail -n +11 huge-file.log

This command tells tail to start printing from the 11th line of huge-file.log, effectively skipping the first 10 lines.

Using sed Command

Another way to achieve this is by using the sed command, which is a powerful text editor that can also be used for filtering. To delete (or skip) the first X lines from a file, you can use:

sed '1,Xd' file.txt

Here, 1,Xd means to delete (d) lines from 1 to X.

Using awk Command

The awk command is a programming language designed for text processing. It’s also capable of skipping initial lines in a file. For instance, to print all lines after the first 1 million lines, you can use:

awk 'NR > 1000000' huge-file.log

Here, NR > 1000000 means that awk should only consider (and thus print) lines whose line number (NR) is greater than 1 million.

Choosing the Right Approach

• For simple line skipping: The tail command with its -n +X option is straightforward and efficient.
• For more complex text processing: If you’re also doing other manipulations, sed or awk might be a better choice due to their powerful filtering capabilities.

Example Usage

Suppose you have a large file named example.log, and you want to print everything except the first 100 lines. Here’s how you can do it:

# Using tail
tail -n +101 example.log

# Using sed
sed '1,100d' example.log

# Using awk (assuming integer numbers)
awk 'NR > 100' example.log

Each of these commands will display the contents of example.log, starting from line 101.

In conclusion, skipping initial lines in a file can be easily achieved with Bash using tools like tail, sed, or awk. The choice of tool depends on your specific needs and preferences.