How to display all the lines from the nth line of a file in unix

Question

I want to display all the lines starting from the nth line. Say, print the third line of a file and all the following lines until end of file. Is there a command for that?

Answer 1

you can use tail

excerpt from the manpage:

 -n, --lines=K output the last K lines, instead of the last 10; or use -n +K to output lines starting with the Kth

for example

tail -n +10 file 

outputs the files content starting with the 10th line

Answer 2

从第 5 行开始显示：

awk 'NR>4' file

Answer 3

sed -n '3,$p' file

这只是填充文本，因为 stackoverflow 不喜欢短命令行。

Answer 4

打印，但删除第 1 到 2 行：

sed '1,2d' filename

Answer 5

You can use awk like this:

awk 'BEGIN{n=5}NR<=n{next}1' file

• BEGIN{n=5} - before file processing starts, sets n to the number of lines to skip (5).
• NR<=n{next} - skips processing if the line number is less than or equal to n .
• 1 - shorthand for print everything else.

Answer 6

The awk command can do this by only printing lines to the NR record number is three or more:

awk 'NR>=3' input_file_name

You can also pass the value into awk using a variable if need be:

awk -v n=3 'NR>=n' input_file_name

(and you can use -vn=${num} to use an environment variable as well).

There are many other tools you can use to do the same job, tail , sed and perl among them or, since this is a programming Q&A site, just roll your own:

#include <stdio.h>

int main (void) {
    // Need character and # of newlines to skip.

    int ch, newlines = 2;

    // Loop until EOF or first lines skipped, exit on EOF.

    while ((ch = getchar()) != EOF)
        if ((ch == '\n') && (--newlines == 0))
            break;

    if (ch == EOF)
        return 0;

    // Now just echo all other characters, then return.

    while ((ch = getchar()) != EOF)
        putchar (ch);

    return 0;
}

Now you wouldn't normally write your own filter program for this but, since you asked for the shortest command, you could use that source code to create an executable called x to do it:

x <input_file_name

You'd be hard-pressed finding a shorter command than that. Of course, assuming you're in a UNIXy environment (specifically, bash ), you could also just:

alias x awk 'NR>=3'

:-)