1 '\" te
   2 .\" Portions Copyright (c) 2013, Joyent, Inc. All Rights Reserved
   3 .\" Copyright (c) 1992, X/Open Company Limited All Rights Reserved Portions
   4 .\" Copyright 1989 AT&T
   5 .\" Portions Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved
   6 .\" Portions Copyright (c) 1982-2007 AT&T Knowledge Ventures
   7 .\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
   8 .\" http://www.opengroup.org/bookstore/.
   9 .\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
  10 .\"  This notice shall appear on any product containing this material.
  11 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
  12 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
  13 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
  14 .TH HEAD 1 "Mar 4, 2013"
  15 .SH NAME
  16 head \- display first few lines of files
  17 .SH SYNOPSIS
  18 .SS "/usr/bin/head"
  19 .LP
  20 .nf
  21 \fB/usr/bin/head\fR [\fB-q\fR] [\fB-v\fR] [\fB-number\fR ] [ \fB-n\fR \fInumber\fR ] [ \fB-c\fR \fInumber\fR] [\fIfilename\fR]...
  22 .fi
  23 
  24 .SS "ksh93"
  25 .LP
  26 .nf
  27 \fBhead\fR [\fB-qv\fR] [\fB-n\fR \fIlines\fR] [\fB-c\fR \fIchars\fR] [\fB-s\fR \fIskip\fR] [\fIfilename\fR]...
  28 .fi
  29 
  30 .SH DESCRIPTION
  31 .SS "/usr/bin/head"
  32 .sp
  33 .LP
  34 The \fBhead\fR utility copies the first \fInumber\fR of lines of each
  35 \fIfilename\fR to the standard output. If no \fIfilename\fR is given,
  36 \fBhead\fR copies lines from the standard input. The default value of
  37 \fInumber\fR is \fB10\fR lines. If \fB-c\fR is specified, \fBhead\fR
  38 copies the first \fInumber\fR of bytes of each filename.
  39 .sp
  40 .LP
  41 When more than one file is specified, the start of each file looks like:
  42 .sp
  43 .in +2
  44 .nf
  45 \fB==>\fR \fIfilename\fR \fB<==\fR
  46 .fi
  47 .in -2
  48 
  49 .sp
  50 .LP
  51 Thus, a common way to display a set of short files, identifying each one, is:
  52 .sp
  53 .in +2
  54 .nf
  55 example% \fBhead -9999 filename1 filename2 ...\fR
  56 .fi
  57 .in -2
  58 .sp
  59 
  60 .SS "ksh93"
  61 .sp
  62 .LP
  63 The \fBhead\fR built-in in \fBksh93\fR is associated with the \fB/bin\fR and
  64 \fB/usr/bin\fR paths. It is invoked when \fBhead\fR is executed without a
  65 pathname prefix and the pathname search finds a \fB/bin/head\fR or
  66 \fB/usr/bin/head\fR executable.
  67 .sp
  68 .LP
  69 \fBhead\fR copies one or more input files to standard output, stopping at a
  70 designated point for each file or to the end of the file whichever comes first.
  71 Copying ends at the point indicated by the options. By default, a header of the
  72 form \fB==> filename <==\fR is output before all but the first file but this
  73 can be changed with the \fB-q\fR and \fB-v\fR options. If no file is given, or
  74 if the file is \fB-\fR, \fBhead\fR copies from standard input starting at the
  75 current location.
  76 .sp
  77 .LP
  78 The option argument for \fB-c\fR and \fB-s\fR can optionally be followed by one
  79 of the following characters to specify a different unit other than a single
  80 byte:
  81 .sp
  82 .ne 2
  83 .na
  84 \fB\fBb\fR\fR
  85 .ad
  86 .RS 5n
  87 512 bytes
  88 .RE
  89 
  90 .sp
  91 .ne 2
  92 .na
  93 \fB\fBk\fR\fR
  94 .ad
  95 .RS 5n
  96 1-kilobyte
  97 .RE
  98 
  99 .sp
 100 .ne 2
 101 .na
 102 \fB\fBm\fR\fR
 103 .ad
 104 .RS 5n
 105 1-megabyte
 106 .RE
 107 
 108 .sp
 109 .LP
 110 For backwards compatibility, \fB-number\fR is equivalent to \fB-n\fR number.
 111 .SH OPTIONS
 112 .SS "/usr/bin/head"
 113 .sp
 114 .LP
 115 The following options are supported by \fB/usr/bin/head\fR:
 116 .sp
 117 .ne 2
 118 .na
 119 \fB\fB-n\fR \fInumber\fR\fR
 120 .ad
 121 .RS 13n
 122 The first \fInumber\fR lines of each input file is copied to standard output.
 123 The \fInumber\fR option-argument must be a positive decimal integer.
 124 .RE
 125 
 126 .sp
 127 .ne 2
 128 .na
 129 \fB\fB-c\fR \fInumber\fR\fR
 130 .ad
 131 .RS 13n
 132 The first \fInumber\fR bytes of each input file is copied to standard output.
 133 The \fInumber\fR option-argument must be a positive decimal integer. Note,
 134 output may end in the middle of a character if a file contains multi-byte
 135 characters.
 136 .RE
 137 
 138 .sp
 139 .ne 2
 140 .na
 141 \fB\fB-\fR\fInumber\fR\fR
 142 .ad
 143 .RS 13n
 144 The \fInumber\fR argument is a positive decimal integer with the same effect as
 145 the \fB-n\fR \fInumber\fR option.
 146 .RE
 147 
 148 .sp
 149 .ne 2
 150 .na
 151 \fB\FB-q\fR\fR
 152 .ad
 153 .RS 13n
 154 \fBhead\fR will not print a header in between each specified file.
 155 .RE
 156 
 157 .sp
 158 .ne 2
 159 .na
 160 \fB\FB-v\fR\fR
 161 .ad
 162 .RS 13n
 163 \fBhead\fR will always print a header in between each specified file.
 164 .RE
 165 
 166 .sp
 167 .LP
 168 If no options are specified, \fBhead\fR acts as if \fB-n\fR \fB10\fR had been
 169 specified.
 170 .SS "ksh93"
 171 .sp
 172 .LP
 173 The following options are supported by the head built-in command in
 174 \fBksh93\fR:
 175 .sp
 176 .ne 2
 177 .na
 178 \fB\fB-n\fR\fR
 179 .ad
 180 .br
 181 .na
 182 \fB\fB--lines=\fR\fIlines\fR\fR
 183 .ad
 184 .RS 18n
 185 Copy lines from each file. The default value is \fB10\fR.
 186 .RE
 187 
 188 .sp
 189 .ne 2
 190 .na
 191 \fB\fB-c\fR\fR
 192 .ad
 193 .br
 194 .na
 195 \fB\fB--bytes=\fR\fIchars\fR\fR
 196 .ad
 197 .RS 18n
 198 Copy \fIchars\fR bytes from each file.
 199 .RE
 200 
 201 .sp
 202 .ne 2
 203 .na
 204 \fB\fB-q\fR\fR
 205 .ad
 206 .br
 207 .na
 208 \fB\fB--quiet|silent\fR\fR
 209 .ad
 210 .RS 18n
 211 Never output filename headers.
 212 .RE
 213 
 214 .sp
 215 .ne 2
 216 .na
 217 \fB\fB-s\fR\fR
 218 .ad
 219 .br
 220 .na
 221 \fB\fB--skip=\fR\fIskip\fR\fR
 222 .ad
 223 .RS 18n
 224 Skip \fIskip\fR characters or lines from each file before copying.
 225 .RE
 226 
 227 .sp
 228 .ne 2
 229 .na
 230 \fB\fB-v\fR\fR
 231 .ad
 232 .br
 233 .na
 234 \fB\fB--verbose\fR\fR
 235 .ad
 236 .RS 18n
 237 Always output filename headers.
 238 .RE
 239 
 240 .SH OPERANDS
 241 .sp
 242 .LP
 243 The following operand is supported:
 244 .sp
 245 .ne 2
 246 .na
 247 \fB\fB\fIfilename\fR\fR\fR
 248 .ad
 249 .RS 12n
 250 A path name of an input file. If no \fIfile\fR operands are specified, the
 251 standard input is used.
 252 .RE
 253 
 254 .SH USAGE
 255 .sp
 256 .LP
 257 See \fBlargefile\fR(5) for the description of the behavior of \fBhead\fR when
 258 encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
 259 .SH EXAMPLES
 260 .LP
 261 \fBExample 1 \fRWriting the First Ten Lines of All Files
 262 .sp
 263 .LP
 264 The following example writes the first ten lines of all files, except those
 265 with a leading period, in the directory:
 266 
 267 .sp
 268 .in +2
 269 .nf
 270 example% \fBhead *\fR
 271 .fi
 272 .in -2
 273 .sp
 274 
 275 .SH ENVIRONMENT VARIABLES
 276 .sp
 277 .LP
 278 See \fBenviron\fR(5) for descriptions of the following environment variables
 279 that affect the execution of \fBhead\fR: \fBLANG\fR, \fBLC_ALL\fR,
 280 \fBLC_CTYPE\fR, \fBLC_MESSAGES\fR, and \fBNLSPATH\fR.
 281 .SH EXIT STATUS
 282 .sp
 283 .LP
 284 The following exit values are returned:
 285 .sp
 286 .ne 2
 287 .na
 288 \fB\fB0\fR\fR
 289 .ad
 290 .RS 6n
 291 Successful completion.
 292 .RE
 293 
 294 .sp
 295 .ne 2
 296 .na
 297 \fB\fB>0\fR\fR
 298 .ad
 299 .RS 6n
 300 An error occurred.
 301 .RE
 302 
 303 .SH ATTRIBUTES
 304 .sp
 305 .LP
 306 See \fBattributes\fR(5) for descriptions of the following attributes:
 307 .SS "/usr/bin/head"
 308 .sp
 309 
 310 .sp
 311 .TS
 312 box;
 313 c | c
 314 l | l .
 315 ATTRIBUTE TYPE  ATTRIBUTE VALUE
 316 _
 317 CSI     Enabled
 318 _
 319 Interface Stability     Committed
 320 _
 321 Standard        See \fBstandards\fR(5).
 322 .TE
 323 
 324 .SS "ksh93"
 325 .sp
 326 
 327 .sp
 328 .TS
 329 box;
 330 c | c
 331 l | l .
 332 ATTRIBUTE TYPE  ATTRIBUTE VALUE
 333 _
 334 Interface Stability     See below.
 335 .TE
 336 
 337 .sp
 338 .LP
 339 The \fBksh93\fR built-in binding to \fB/bin\fR and \fB/usr/bin\fR is Volatile.
 340 The built-in interfaces are Uncommitted.
 341 .SH SEE ALSO
 342 .sp
 343 .LP
 344 \fBcat\fR(1), \fBksh93\fR(1), \fBmore\fR(1), \fBpg\fR(1), \fBtail\fR(1),
 345 \fBattributes\fR(5), \fBenviron\fR(5), \fBlargefile\fR(5), \fBstandards\fR(5)