Name | Synopsis | Description | Options | Operands | Usage | Examples | Environment Variables | Exit Status | Attributes | See Also
/usr/bin/head [-number | -n number] [filename]...
head [-qv] [-n lines] [-c chars] [-s skip][filename]...
==> filename <==
Thus, a common way to display a set of short files, identifying each one, is:
example% head -9999 filename1 filename2 ... |
The head built-in in ksh93 is associated with the /bin and /usr/bin paths. It is invoked when head is executed without a pathname prefix and the pathname search finds a /bin/head or /usr/bin/head executable.
head copies one or more input files to standard output, stopping at a designated point for each file or to the end of the file whichever comes first. Copying ends at the point indicated by the options. By default, a header of the form ==> filename <== is output before all but the first file but this can be changed with the -q and -v options. If no file is given, or if the file is -, head copies from standard input starting at the current location.
The option argument for -c and -s can optionally be followed by one of the following characters to specify a different unit other than a single byte:
512 bytes
1-kilobyte
1-megabyte
For backwards compatibility, -number is equivalent to -n number.
The following options are supported by /usr/bin/head:
The first number lines of each input file is copied to standard output. The number option-argument must be a positive decimal integer.
The number argument is a positive decimal integer with the same effect as the -n number option.
If no options are specified, head acts as if -n 10 had been specified.
The following options are supported by the head built-in command in ksh93:
Copy lines from each file. The default value is 10.
Copy chars bytes from each file.
Never output filename headers.
Skip skip characters or lines from each file before copying.
Always output filename headers.
The following operand is supported:
A path name of an input file. If no file operands are specified, the standard input is used.
See largefile(5) for the description of the behavior of head when encountering files greater than or equal to 2 Gbyte ( 231 bytes).
The following example writes the first ten lines of all files, except those with a leading period, in the directory:
example% head * |
See environ(5) for descriptions of the following environment variables that affect the execution of head: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
---|---|
Availability |
SUNWcsu |
CSI |
Enabled |
Interface Stability |
Committed |
Standard |
See standards(5). |
Name | Synopsis | Description | Options | Operands | Usage | Examples | Environment Variables | Exit Status | Attributes | See Also