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.TH head 1 "2 Nov 2007" "SunOS 5.11" "User Commands"
.SH NAME
head \- display first few lines of files
.SH SYNOPSIS
.SS "/usr/bin/head"
.LP
.nf
\fB/usr/bin/head\fR [\fB-number\fR | \fB-n\fR \fInumber\fR] [\fIfilename\fR]...
.fi

.SS "ksh93"
.LP
.nf
\fBhead\fR [\fB-qv\fR] [\fB-n\fR \fIlines\fR] [\fB-c\fR \fIchars\fR] [\fB-s\fR \fIskip\fR][\fIfilename\fR]...
.fi

.SH DESCRIPTION
.SS "/usr/bin/head"
.sp
.LP
The \fBhead\fR utility copies the first \fInumber\fR of lines of each
\fIfilename\fR to the standard output. If no \fIfilename\fR is given,
\fBhead\fR copies lines from the standard input. The default value of
\fInumber\fR is \fB10\fR lines.
.sp
.LP
When more than one file is specified, the start of each file looks like:
.sp
.in +2
.nf
\fB==>\fR \fIfilename\fR \fB<==\fR
.fi
.in -2

.sp
.LP
Thus, a common way to display a set of short files, identifying each one, is:
.sp
.in +2
.nf
example% \fBhead -9999 filename1 filename2 ...\fR
.fi
.in -2
.sp

.SS "ksh93"
.sp
.LP
The \fBhead\fR built-in in \fBksh93\fR is associated with the \fB/bin\fR and
\fB/usr/bin\fR paths. It is invoked when \fBhead\fR is executed without a
pathname prefix and the pathname search finds a \fB/bin/head\fR or
\fB/usr/bin/head\fR executable.
.sp
.LP
\fBhead\fR 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 \fB==> filename <==\fR is output before all but the first file but this
can be changed with the \fB-q\fR and \fB-v\fR options. If no file is given, or
if the file is \fB-\fR, \fBhead\fR copies from standard input starting at the
current location.
.sp
.LP
The option argument for \fB-c\fR and \fB-s\fR can optionally be followed by one
of the following characters to specify a different unit other than a single
byte:
.sp
.ne 2
.mk
.na
\fB\fBb\fR\fR
.ad
.RS 5n
.rt  
512 bytes
.RE

.sp
.ne 2
.mk
.na
\fB\fBk\fR\fR
.ad
.RS 5n
.rt  
1-kilobyte
.RE

.sp
.ne 2
.mk
.na
\fB\fBm\fR\fR
.ad
.RS 5n
.rt  
1-megabyte
.RE

.sp
.LP
For backwards compatibility, \fB-number\fR is equivalent to \fB-n\fR number.
.SH OPTIONS
.SS "/usr/bin/head"
.sp
.LP
The following options are supported by \fB/usr/bin/head\fR:
.sp
.ne 2
.mk
.na
\fB\fB-n\fR \fInumber\fR\fR
.ad
.RS 13n
.rt  
The first \fInumber\fR lines of each input file is copied to standard output.
The \fInumber\fR option-argument must be a positive decimal integer.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-\fR\fInumber\fR\fR
.ad
.RS 13n
.rt  
The \fInumber\fR argument is a positive decimal integer with the same effect as
the \fB-n\fR \fInumber\fR option.
.RE

.sp
.LP
If no options are specified, \fBhead\fR acts as if \fB-n\fR \fB10\fR had been
specified.
.SS "ksh93"
.sp
.LP
The following options are supported by the head built-in command in
\fBksh93\fR:
.sp
.ne 2
.mk
.na
\fB\fB-n\fR\fR
.ad
.br
.na
\fB\fB--lines=\fR\fIlines\fR\fR
.ad
.RS 18n
.rt  
Copy lines from each file. The default value is \fB10\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-c\fR\fR
.ad
.br
.na
\fB\fB--bytes=\fR\fIchars\fR\fR
.ad
.RS 18n
.rt  
Copy \fIchars\fR bytes from each file.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-q\fR\fR
.ad
.br
.na
\fB\fB--quiet|silent\fR\fR
.ad
.RS 18n
.rt  
Never output filename headers.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-s\fR\fR
.ad
.br
.na
\fB\fB--skip=\fR\fIskip\fR\fR
.ad
.RS 18n
.rt  
Skip \fIskip\fR characters or lines from each file before copying.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-v\fR\fR
.ad
.br
.na
\fB\fB--verbose\fR\fR
.ad
.RS 18n
.rt  
Always output filename headers.
.RE

.SH OPERANDS
.sp
.LP
The following operand is supported:
.sp
.ne 2
.mk
.na
\fB\fB\fIfilename\fR\fR\fR
.ad
.RS 12n
.rt  
A path name of an input file. If no \fIfile\fR operands are specified, the
standard input is used.
.RE

.SH USAGE
.sp
.LP
See \fBlargefile\fR(5) for the description of the behavior of \fBhead\fR when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
.SH EXAMPLES
.LP
\fBExample 1 \fRWriting the First Ten Lines of All Files
.sp
.LP
The following example writes the first ten lines of all files, except those
with a leading period, in the directory:

.sp
.in +2
.nf
example% \fBhead *\fR
.fi
.in -2
.sp

.SH ENVIRONMENT VARIABLES
.sp
.LP
See \fBenviron\fR(5) for descriptions of the following environment variables
that affect the execution of \fBhead\fR: \fBLANG\fR, \fBLC_ALL\fR,
\fBLC_CTYPE\fR, \fBLC_MESSAGES\fR, and \fBNLSPATH\fR.
.SH EXIT STATUS
.sp
.LP
The following exit values are returned:
.sp
.ne 2
.mk
.na
\fB\fB0\fR\fR
.ad
.RS 6n
.rt  
Successful completion.
.RE

.sp
.ne 2
.mk
.na
\fB\fB>0\fR\fR
.ad
.RS 6n
.rt  
An error occurred.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.SS "/usr/bin/head"
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
CSIEnabled
_
Interface StabilityCommitted
_
StandardSee \fBstandards\fR(5).
.TE

.SS "ksh93"
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilitySee below.
.TE

.sp
.LP
The \fBksh93\fR built-in binding to \fB/bin\fR and \fB/usr/bin\fR is Volatile.
The built-in interfaces are Uncommitted.
.SH SEE ALSO
.sp
.LP
\fBcat\fR(1), \fBksh93\fR(1), \fBmore\fR(1), \fBpg\fR(1), \fBtail\fR(1),
\fBattributes\fR(5), \fBenviron\fR(5), \fBlargefile\fR(5), \fBstandards\fR(5)