Linux and Unix head command
head makes it easy to output the first part of files.
head, by default, prints the first 10 lines of each FILE to standard output. With more than one FILE, it precedes each set of output with a header identifying the file name. If no FILE is specified, or when FILE is specified as a dash ("-"), head reads from standard input.
head [OPTION]... [FILE]...
|-c, --bytes=[-]num||print the first num bytes of each file; with a leading '-', print all but the last num bytes of each file.|
|-n, --lines=[-]num||print the first num lines instead of the first 10; with the leading '-', print all but the last num lines of each file.|
|-q, --quiet, --silent||never print headers identifying file names.|
|-v, --verbose||always print headers identifying file names.|
|--help||display a help message and exit.|
|--version||output version information and exit.|
In the above options, num may have a multiplier suffix:
Display the first ten lines of myfile.txt.
head -15 myfile.txt
Display the first fifteen lines of myfile.txt.
head myfile.txt myfile2.txt
Display the first ten lines of both myfile.txt and myfile2.txt, with a header before each that indicates the filename.
head -n 5 myfile.txt myfile2.txt
Displays only the first 5 lines of both files.
head -c 20 myfile.txt
head -n 5K myfile.txt
Displays the first 5,000 lines of myfile.txt.
head -c 6M myfile.txt
Displays the first six megabytes.
If a dash is specified for the filename, head reads from standard input rather than a regular file.
head myfile.txt myfile2.txt -
Display the first ten lines of myfile.txt, myfile2.txt, and standard input.
head -n 4 *.txt
Display the first four lines of every file in the working directory whose filename ends in the extension .txt.
head -n 4 -q *.txt
Same as the previous command, but uses quiet (-q) output, which will not print a header before the lines of each individual file.