touch/touch.1

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  37 .\"     @(#)touch.1     8.3 (Berkeley) 4/28/95
  38 .\"
  39 .Dd April 28, 1995
  40 .Dt TOUCH 1
  41 .Os
  42 .Sh NAME
  43 .Nm touch
  44 .Nd change file access and modification times
  45 .Sh SYNOPSIS
  46 .Nm
  47 .Op Fl acfhm
  48 .Op Fl r Ar file
  49 .Op Fl t Ar [[CC]YY]MMDDhhmm[.SS]
  50 .Ar file ...
  51 .Sh DESCRIPTION
  52 The
  53 .Nm
  54 utility sets the modification and access times of files to the
  55 current time of day.
  56 If the file doesn't exist, it is created with default permissions.
  57 .Pp
  58 The following options are available:
  59 .Bl -tag -width Ds
  60 .It Fl a
  61 Change the access time of the file.
  62 The modification time of the file is not changed unless the
  63 .Fl m
  64 flag is also specified.
  65 .It Fl c
  66 Do not create the file if it does not exist.
  67 The
  68 .Nm
  69 utility does not treat this as an error.
  70 No error messages are displayed and the exit value is not affected.
  71 .It Fl f
  72 Attempt to force the update, even if the file permissions do not
  73 currently permit it.
  74 .It Fl h
  75 If
  76 .Ar file
  77 is a symbolic link, access and/or modification time of the link is changed.
  78 This option implies
  79 .Fl c .
  80 .It Fl m
  81 Change the modification time of the file.
  82 The access time of the file is not changed unless the
  83 .Fl a
  84 flag is also specified.
  85 .It Fl r
  86 Use the access and modifications times from the specified file
  87 instead of the current time of day.
  88 .It Fl t
  89 Change the access and modification times to the specified time.
  90 The argument should be in the form
  91 .Dq [[CC]YY]MMDDhhmm[.SS]
  92 where each pair of letters represents the following:
  93 .Pp
  94 .Bl -tag -width Ds -compact -offset indent
  95 .It Ar CC
  96 The first two digits of the year (the century).
  97 .It Ar YY
  98 The second two digits of the year.
  99 If
 100 .Dq YY
 101 is specified, but
 102 .Dq CC
 103 is not, a value for
 104 .Dq YY
 105 between 69 and 99 results in a
 106 .Dq CC
 107 value of 19.
 108 Otherwise, a
 109 .Dq CC
 110 value of 20 is used.
 111 .It Ar MM
 112 The month of the year, from 1 to 12.
 113 .It Ar DD
 114 The day of the month, from 1 to 31.
 115 .It Ar hh
 116 The hour of the day, from 0 to 23.
 117 .It Ar mm
 118 The minute of the hour, from 0 to 59.
 119 .It Ar SS
 120 The second of the minute, from 0 to 61.
 121 .El
 122 .Pp
 123 If the
 124 .Dq CC
 125 and
 126 .Dq YY
 127 letter pairs are not specified, the values default to the current
 128 year.
 129 If the
 130 .Dq SS
 131 letter pair is not specified, the value defaults to 0.
 132 .El
 133 .Pp
 134 The
 135 .Nm
 136 utility exits 0 on success, and >0 if an error occurs.
 137 .Sh SEE ALSO
 138 .Xr utimes 2
 139 .Sh COMPATIBILITY
 140 The obsolescent form of
 141 .Nm "" ,
 142 where a time format is specified as the first argument, is supported.
 143 When no
 144 .Fl r
 145 or
 146 .Fl t
 147 option is specified, there are at least two arguments, and the first
 148 argument is a string of digits either eight or ten characters in length,
 149 the first argument is interpreted as a time specification of the form
 150 .Dq MMDDhhmm[YY] .
 151 .Pp
 152 The
 153 .Dq MM ,
 154 .Dq DD ,
 155 .Dq hh
 156 and
 157 .Dq mm
 158 letter pairs are treated as their counterparts specified to the
 159 .Fl t
 160 option.
 161 If the
 162 .Dq YY
 163 letter pair is in the range 69 to 99, the year is set to 1969 to 1999,
 164 otherwise, the year is set in the 21st century.
 165 .Sh STANDARDS
 166 The
 167 .Nm
 168 utility is expected to be a superset of the
 169 .St -p1003.2
 170 specification.
 171 .Sh HISTORY
 172 A
 173 .Nm
 174 utility appeared in
 175 .At v7 .
 176 .Sh BUGS
 177 A symbolic link can't be a reference file of access and/or modification time.