Annotation of src/usr.bin/head/head.1, Revision 1.21
1.21 ! tedu 1: .\" $OpenBSD: head.1,v 1.20 2014/03/21 11:20:41 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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1.21 ! tedu 32: .Dd $Mdocdate: March 21 2014 $
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
1.18 jmc 40: .Op Fl Ns Ar count | Fl n Ar count
1.1 deraadt 41: .Op Ar
42: .Sh DESCRIPTION
1.4 aaron 43: The
44: .Nm
45: utility copies the first
1.1 deraadt 46: .Ar count
1.4 aaron 47: lines of each specified
48: .Ar file
49: to the standard output.
1.5 aaron 50: If no files are named,
1.4 aaron 51: .Nm
52: copies lines from the standard input.
1.1 deraadt 53: If
54: .Ar count
1.4 aaron 55: is omitted, it defaults to 10.
56: .Pp
57: The options are as follows:
58: .Bl -tag -width Ds
1.18 jmc 59: .It Fl Ns Ar count | Fl n Ar count
1.4 aaron 60: Copy the first
61: .Ar count
62: lines of each input file to the standard output.
63: .Ar count
64: must be a positive decimal integer.
65: .El
66: .Pp
67: If more than one file is specified,
68: .Nm
69: precedes the output of each file with the following, in order to distinguish
70: the head of each file:
71: .Pp
72: .Dl ==> Ar file No <==
1.17 jmc 73: .Sh EXIT STATUS
1.16 jmc 74: .Ex -std head
1.4 aaron 75: .Sh EXAMPLES
76: To display the first 500 lines of the file
77: .Ar foo :
78: .Pp
1.20 jmc 79: .Dl $ head -n 500 foo
1.4 aaron 80: .Pp
81: .Nm
82: can be used in conjunction with
83: .Xr tail 1
84: in the following way to, for example, display only line 500 from the file
85: .Ar foo :
86: .Pp
1.20 jmc 87: .Dl $ head -n 500 foo | tail -1
1.1 deraadt 88: .Sh SEE ALSO
1.4 aaron 89: .Xr cat 1 ,
1.21 ! tedu 90: .Xr cut 1 ,
1.4 aaron 91: .Xr less 1 ,
92: .Xr more 1 ,
1.1 deraadt 93: .Xr tail 1
1.12 jmc 94: .Sh STANDARDS
1.3 aaron 95: The
96: .Nm
1.13 jmc 97: utility is compliant with the
1.15 jmc 98: .St -p1003.1-2008
1.13 jmc 99: specification.
100: .Pp
1.20 jmc 101: The historic syntax
102: .Fl Ns Ar count
103: is supported by this implementation.
1.1 deraadt 104: .Sh HISTORY
105: The
1.3 aaron 106: .Nm
1.19 schwarze 107: utility first appeared in
108: .Bx 1 .
109: .Sh AUTHORS
110: .An Bill Joy ,
111: August 24, 1977.