raw/mann/proc.n

   1 '\"
   2 '\" Copyright (c) 1993 The Regents of the University of California.
   3 '\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
   4 '\"
   5 '\" See the file "license.terms" for information on usage and redistribution
   6 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
   7 '\"
   8 '\" RCS: @(#) $Id: proc.n,v 1.1 2003/12/20 03:31:54 bbbush Exp $
   9 '\"
  10 '\" The definitions below are for supplemental macros used in Tcl/Tk
  11 '\" manual entries.
  12 '\"
  13 '\" .AP type name in/out ?indent?
  14 '\"     Start paragraph describing an argument to a library procedure.
  15 '\"     type is type of argument (int, etc.), in/out is either "in", "out",
  16 '\"     or "in/out" to describe whether procedure reads or modifies arg,
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  61 '\"
  62 '\" .OP cmdName dbName dbClass
  63 '\"     Start of description of a specific option.  cmdName gives the
  64 '\"     option's name as specified in the class command, dbName gives
  65 '\"     the option's name in the option database, and dbClass gives
  66 '\"     the option's class in the option database.
  67 '\"
  68 '\" .UL arg1 arg2
  69 '\"     Print arg1 underlined, then print arg2 normally.
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  71 '\" RCS: @(#) $Id: proc.n,v 1.1 2003/12/20 03:31:54 bbbush Exp $
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  73 '\"     # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
  74 .if t .wh -1.3i ^B
  75 .nr ^l \n(.l
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  80 .el \{\
  81 .   ie !"\\$2"" .TP \\n()Cu
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  83 .\}
  84 .ta \\n()Au \\n()Bu
  85 .ie !"\\$3"" \{\
  86 \&\\$1  \\fI\\$2\\fP    (\\$3)
  87 .\".b
  88 .\}
  89 .el \{\
  90 .br
  91 .ie !"\\$2"" \{\
  92 \&\\$1  \\fI\\$2\\fP
  93 .\}
  94 .el \{\
  95 \&\\fI\\$1\\fP
  96 .\}
  97 .\}
  98 ..
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 104 .\"
 105 .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
 106 .nr )C \\n()Bu+\\w'(in/out)'u+2n
 107 ..
 108 .AS Tcl_Interp Tcl_CreateInterp in/out
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 132 .\}
 133 .el \}\
 134 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
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 178 .\}
 179 .if \\n(^v \{\
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 182 .\}
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 206 '\"     # SO - start of list of standard options
 207 .de SO
 208 .SH "STANDARD OPTIONS"
 209 .LP
 210 .nf
 211 .ta 5.5c 11c
 212 .ft B
 213 ..
 214 '\"     # SE - end of list of standard options
 215 .de SE
 216 .fi
 217 .ft R
 218 .LP
 219 See the \\fBoptions\\fR manual entry for details on the standard options.
 220 ..
 221 '\"     # OP - start of full description for a single option
 222 .de OP
 223 .LP
 224 .nf
 225 .ta 4c
 226 Command-Line Name:      \\fB\\$1\\fR
 227 Database Name:  \\fB\\$2\\fR
 228 Database Class: \\fB\\$3\\fR
 229 .fi
 230 .IP
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 241 .RE
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 243 .de UL
 244 \\$1\l'|0\(ul'\\$2
 245 ..
 246 .TH proc n "" Tcl "Tcl Built-In Commands"
 247 .BS
 248 '\" Note:  do not modify the .SH NAME line immediately below!
 249 .SH NAME
 250 proc \- Create a Tcl procedure
 251 .SH SYNOPSIS
 252 \fBproc \fIname args body\fR
 253 .BE
 254
 255 .SH DESCRIPTION
 256 .PP
 257 The \fBproc\fR command creates a new Tcl procedure named
 258 \fIname\fR, replacing
 259 any existing command or procedure there may have been by that name.
 260 Whenever the new command is invoked, the contents of \fIbody\fR will
 261 be executed by the Tcl interpreter.
 262 Normally, \fIname\fR is unqualified
 263 (does not include the names of any containing namespaces),
 264 and the new procedure is created in the current namespace.
 265 If \fIname\fR includes any namespace qualifiers,
 266 the procedure is created in the specified namespace.
 267 \fIArgs\fR specifies the formal arguments to the
 268 procedure.  It consists of a list, possibly empty, each of whose
 269 elements specifies
 270 one argument.  Each argument specifier is also a list with either
 271 one or two fields.  If there is only a single field in the specifier
 272 then it is the name of the argument; if there are two fields, then
 273 the first is the argument name and the second is its default value.
 274 .PP
 275 When \fIname\fR is invoked a local variable
 276 will be created for each of the formal arguments to the procedure; its
 277 value will be the value of corresponding argument in the invoking command
 278 or the argument's default value.
 279 Arguments with default values need not be
 280 specified in a procedure invocation.  However, there must be enough
 281 actual arguments for all the
 282 formal arguments that don't have defaults, and there must not be any extra
 283 actual arguments.  There is one special case to permit procedures with
 284 variable numbers of arguments.  If the last formal argument has the name
 285 \fBargs\fR, then a call to the procedure may contain more actual arguments
 286 than the procedure has formals.  In this case, all of the actual arguments
 287 starting at the one that would be assigned to \fBargs\fR are combined into
 288 a list (as if the \fBlist\fR command had been used); this combined value
 289 is assigned to the local variable \fBargs\fR.
 290 .PP
 291 When \fIbody\fR is being executed, variable names normally refer to
 292 local variables, which are created automatically when referenced and
 293 deleted when the procedure returns.  One local variable is automatically
 294 created for each of the procedure's arguments.
 295 Global variables can only be accessed by invoking
 296 the \fBglobal\fR command or the \fBupvar\fR command.
 297 Namespace variables can only be accessed by invoking
 298 the \fBvariable\fR command or the \fBupvar\fR command.
 299 .PP
 300 The \fBproc\fR command returns an empty string.  When a procedure is
 301 invoked, the procedure's return value is the value specified in a
 302 \fBreturn\fR command.  If the procedure doesn't execute an explicit
 303 \fBreturn\fR, then its return value is the value of the last command
 304 executed in the procedure's body.
 305 If an error occurs while executing the procedure
 306 body, then the procedure-as-a-whole will return that same error.
 307
 308 .SH "SEE ALSO"
 309 info(n), unknown(n)
 310
 311 .SH KEYWORDS
 312 argument, procedure