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Diffstat (limited to 'doc/global.n')
| -rw-r--r-- | doc/global.n | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/doc/global.n b/doc/global.n index 252cbfb..aa8f2e4 100644 --- a/doc/global.n +++ b/doc/global.n @@ -5,31 +5,54 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: global.n,v 1.2 1998/09/14 18:39:53 stanton Exp $ -'\" -.so man.macros .TH global n "" Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME global \- Access global variables .SH SYNOPSIS -\fBglobal \fIvarname \fR?\fIvarname ...\fR? +\fBglobal \fR?\fIvarname ...\fR? .BE - .SH DESCRIPTION .PP -This command is ignored unless a Tcl procedure is being interpreted. -If so then it declares the given \fIvarname\fR's to be global variables -rather than local ones. -Global variables are variables in the global namespace. -For the duration of the current procedure -(and only while executing in the current procedure), -any reference to any of the \fIvarname\fRs -will refer to the global variable by the same name. - +This command has no effect unless executed in the context of a proc body. +If the \fBglobal\fR command is executed in the context of a proc body, it +creates local variables linked to the corresponding global variables (though +these linked variables, like those created by \fBupvar\fR, are not included +in the list returned by \fBinfo locals\fR). +.PP +If \fIvarname\fR contains namespace qualifiers, the local variable's name is +the unqualified name of the global variable, as determined by the +\fBnamespace tail\fR command. +.PP +\fIvarname\fR is always treated as the name of a variable, not an +array element. An error is returned if the name looks like an array element, +such as \fBa(b)\fR. +.SH EXAMPLES +.PP +This procedure sets the namespace variable \fI::a::x\fR +.PP +.CS +proc reset {} { + \fBglobal\fR a::x + set x 0 +} +.CE +.PP +This procedure accumulates the strings passed to it in a global +buffer, separated by newlines. It is useful for situations when you +want to build a message piece-by-piece (as if with \fBputs\fR) but +send that full message in a single piece (e.g. over a connection +opened with \fBsocket\fR or as part of a counted HTTP response). +.PP +.CS +proc accum {string} { + \fBglobal\fR accumulator + append accumulator $string \en +} +.CE .SH "SEE ALSO" -namespace(n), variable(n) - +namespace(n), upvar(n), variable(n) .SH KEYWORDS global, namespace, procedure, variable |