Annotation of src/usr.bin/head/head.1, Revision 1.15
1.15 ! jmc 1: .\" $OpenBSD: head.1,v 1.14 2007/05/31 19:20:11 jmc Exp $
1.7 aaron 2: .\"
1.1 deraadt 3: .\" Copyright (c) 1980, 1990 The Regents of the University of California.
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1.11 millert 14: .\" 3. Neither the name of the University nor the names of its contributors
1.1 deraadt 15: .\" may be used to endorse or promote products derived from this software
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1.15 ! jmc 32: .Dd $Mdocdate: May 31 2007 $
1.1 deraadt 33: .Dt HEAD 1
34: .Os
35: .Sh NAME
36: .Nm head
1.4 aaron 37: .Nd display first few lines of files
1.1 deraadt 38: .Sh SYNOPSIS
39: .Nm head
1.4 aaron 40: .Oo
41: .Fl Ns Ar count No \&|
42: .Fl n Ar count
43: .Oc
1.1 deraadt 44: .Op Ar
45: .Sh DESCRIPTION
1.4 aaron 46: The
47: .Nm
48: utility copies the first
1.1 deraadt 49: .Ar count
1.4 aaron 50: lines of each specified
51: .Ar file
52: to the standard output.
1.5 aaron 53: If no files are named,
1.4 aaron 54: .Nm
55: copies lines from the standard input.
1.1 deraadt 56: If
57: .Ar count
1.4 aaron 58: is omitted, it defaults to 10.
59: .Pp
60: The options are as follows:
61: .Bl -tag -width Ds
62: .It Xo Fl Ns Ar count No \&|
63: .Fl n Ar count
64: .Xc
65: Copy the first
66: .Ar count
67: lines of each input file to the standard output.
68: .Ar count
69: must be a positive decimal integer.
70: .El
71: .Pp
72: If more than one file is specified,
73: .Nm
74: precedes the output of each file with the following, in order to distinguish
75: the head of each file:
76: .Pp
77: .Dl ==> Ar file No <==
78: .Sh EXAMPLES
79: To display the first 500 lines of the file
80: .Ar foo :
81: .Pp
82: .Dl $ head -500 foo
83: .Pp
84: .Nm
85: can be used in conjunction with
86: .Xr tail 1
87: in the following way to, for example, display only line 500 from the file
88: .Ar foo :
89: .Pp
90: .Dl $ head -500 foo | tail -1
1.1 deraadt 91: .Sh SEE ALSO
1.4 aaron 92: .Xr cat 1 ,
93: .Xr less 1 ,
94: .Xr more 1 ,
1.1 deraadt 95: .Xr tail 1
1.12 jmc 96: .Sh STANDARDS
1.3 aaron 97: The
98: .Nm
1.13 jmc 99: utility is compliant with the
1.15 ! jmc 100: .St -p1003.1-2008
1.13 jmc 101: specification.
102: .Pp
103: The historic command line syntax is supported by this implementation.
1.1 deraadt 104: .Sh HISTORY
105: The
1.3 aaron 106: .Nm
1.1 deraadt 107: utility appeared in
108: .Bx 3.0 .