- head(1) — Linux man page
- Author
- Reporting Bugs
- Copyright
- See Also
- Man head in linux
- DESCRIPTION
- OPTIONS
- OPERANDS
- STDIN
- INPUT FILES
- ENVIRONMENT VARIABLES
- ASYNCHRONOUS EVENTS
- STDOUT
- STDERR
- OUTPUT FILES
- EXTENDED DESCRIPTION
- EXIT STATUS
- CONSEQUENCES OF ERRORS
- APPLICATION USAGE
- EXAMPLES
- RATIONALE
- DESCRIPTION
- AUTHOR
- REPORTING BUGS
- COPYRIGHT
- SEE ALSO
- Man head in linux
- DESCRIPTION
- OPTIONS
- OPERANDS
- STDIN
- INPUT FILES
- ENVIRONMENT VARIABLES
- ASYNCHRONOUS EVENTS
- STDOUT
- STDERR
- OUTPUT FILES
- EXTENDED DESCRIPTION
- EXIT STATUS
- CONSEQUENCES OF ERRORS
- APPLICATION USAGE
- EXAMPLES
- RATIONALE
head(1) — Linux man page
Print the first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too. -c, —bytes=[-]K print the first K bytes of each file; with the leading ‘-‘, print all but the last K bytes of each file -n, —lines=[-]K print the first K lines instead of the first 10; with the leading ‘-‘, print all but the last K lines of each file -q, —quiet, —silent never print headers giving file names -v, —verbose always print headers giving file names —help display this help and exit —version output version information and exit
K may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y.
Author
Reporting Bugs
Copyright
Copyright © 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later .
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
See Also
The full documentation for head is maintained as a Texinfo manual. If the info and head programs are properly installed at your site, the command info coreutils aqhead invocationaq
should give you access to the complete manual.
Man head in linux
DESCRIPTION
The head utility shall copy its input files to the standard output, ending the output for each file at a designated point.
Copying shall end at the point in each input file indicated by the -n number option. The option-argument number shall be counted in units of lines.
OPTIONS
The head utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
The following option shall be supported: -n number The first number lines of each input file shall be copied to standard output. The application shall ensure that the number option-argument is a positive decimal integer.
When a file contains less than number lines, it shall be copied to standard output in its entirety. This shall not be an error.
If no options are specified, head shall act as if -n 10 had been specified.
OPERANDS
The following operand shall be supported: file A pathname of an input file. If no file operands are specified, the standard input shall be used.
STDIN
The standard input shall be used only if no file operands are specified. See the INPUT FILES section.
INPUT FILES
Input files shall be text files, but the line length is not restricted to bytes.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of head : LANG Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.) LC_ALL If set to a non-empty string value, override the values of all the other internationalization variables. LC_CTYPE Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments and input files). LC_MESSAGES Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error. NLSPATH Determine the location of message catalogs for the processing of LC_MESSAGES .
ASYNCHRONOUS EVENTS
STDOUT
The standard output shall contain designated portions of the input files.
If multiple file operands are specified, head shall precede the output for each with the header:
except that the first header written shall not include the initial .
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
EXTENDED DESCRIPTION
EXIT STATUS
The following exit values shall be returned: 0 Successful completion. >0 An error occurred.
CONSEQUENCES OF ERRORS
The following sections are informative.
APPLICATION USAGE
The obsolescent — number form is withdrawn in this version. Applications should use the -n number option.
EXAMPLES
To write the first ten lines of all files (except those with a leading period) in the directory:
RATIONALE
Although it is possible to simulate head with sed 10q for a single file, the standard developers decided that the popularity of head on historical BSD systems warranted its inclusion alongside tail .
This standard version of head follows the Utility Syntax Guidelines. The -n option was added to this new interface so that head and tail would be more logically related.
There is no -c option (as there is in tail ) because it is not historical practice and because other utilities in this volume of IEEE Std 1003.1-2001 provide similar functionality.
DESCRIPTION
Print the first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too.
-c, —bytes=[-]NUM print the first NUM bytes of each file; with the 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 giving file names -v, —verbose always print headers giving file names -z, —zero-terminated line delimiter is NUL, not newline —help display this help and exit —version output version information and exit
NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y, R, Q. Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
AUTHOR
Written by David MacKenzie and Jim Meyering.
REPORTING BUGS
COPYRIGHT
Copyright © 2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later https://gnu.org/licenses/gpl.html.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation https://www.gnu.org/software/coreutils/head
or available locally via: info ‘(coreutils) head invocation’
Powered by archmanweb, using mandoc for the conversion of manual pages.
The website is available under the terms of the GPL-3.0 license, except for the contents of the manual pages, which have their own license specified in the corresponding Arch Linux package.
Man head in linux
DESCRIPTION
The head utility shall copy its input files to the standard output, ending the output for each file at a designated point.
Copying shall end at the point in each input file indicated by the -n number option. The option-argument number shall be counted in units of lines.
OPTIONS
The head utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
The following option shall be supported: -n number The first number lines of each input file shall be copied to standard output. The application shall ensure that the number option-argument is a positive decimal integer.
When a file contains less than number lines, it shall be copied to standard output in its entirety. This shall not be an error.
If no options are specified, head shall act as if -n 10 had been specified.
OPERANDS
The following operand shall be supported: file A pathname of an input file. If no file operands are specified, the standard input shall be used.
STDIN
The standard input shall be used only if no file operands are specified. See the INPUT FILES section.
INPUT FILES
Input files shall be text files, but the line length is not restricted to bytes.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of head : LANG Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.) LC_ALL If set to a non-empty string value, override the values of all the other internationalization variables. LC_CTYPE Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments and input files). LC_MESSAGES Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error. NLSPATH Determine the location of message catalogs for the processing of LC_MESSAGES .
ASYNCHRONOUS EVENTS
STDOUT
The standard output shall contain designated portions of the input files.
If multiple file operands are specified, head shall precede the output for each with the header:
except that the first header written shall not include the initial .
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
EXTENDED DESCRIPTION
EXIT STATUS
The following exit values shall be returned: 0 Successful completion. >0 An error occurred.
CONSEQUENCES OF ERRORS
The following sections are informative.
APPLICATION USAGE
The obsolescent — number form is withdrawn in this version. Applications should use the -n number option.
EXAMPLES
To write the first ten lines of all files (except those with a leading period) in the directory:
RATIONALE
Although it is possible to simulate head with sed 10q for a single file, the standard developers decided that the popularity of head on historical BSD systems warranted its inclusion alongside tail .
This standard version of head follows the Utility Syntax Guidelines. The -n option was added to this new interface so that head and tail would be more logically related.
There is no -c option (as there is in tail ) because it is not historical practice and because other utilities in this volume of IEEE Std 1003.1-2001 provide similar functionality.