When looking into a large file, which consists of thousands of lines, we will not use a command such as cat to print the entire file contents. Instead we look for a sample (for example, the first 10 lines of the file or the last 10 lines of the file). We may need to print the first n lines or last n lines and even print all the lines except the last n lines or all lines except first n lines.
Another use case is to print lines from mth to nth lines.
The commands head and tail can help us do this.
The head command always reads the header portion of the input file.
Print the first 10 lines as follows:
$ head fileRead the data from
stdinas follows:$ cat text | headSpecify the number of first lines to be printed as follows:
$ head -n 4 fileThis command prints four lines.
Print all lines excluding the last
Mlines as follows:$ head -n -M fileFor example, to print all the lines except the...