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-rw-r--r--doc/subst.n74
1 files changed, 48 insertions, 26 deletions
diff --git a/doc/subst.n b/doc/subst.n
index 71b17f6..75fe00f 100644
--- a/doc/subst.n
+++ b/doc/subst.n
@@ -6,7 +6,7 @@
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
-'\" RCS: @(#) $Id: subst.n,v 1.5.2.1 2004/10/27 14:23:58 dkf Exp $
+'\" RCS: @(#) $Id: subst.n,v 1.16 2007/12/13 15:22:33 dgp Exp $
'\"
.so man.macros
.TH subst n 7.4 Tcl "Tcl Built-In Commands"
@@ -17,7 +17,6 @@ subst \- Perform backslash, command, and variable substitutions
.SH SYNOPSIS
\fBsubst \fR?\fB\-nobackslashes\fR? ?\fB\-nocommands\fR? ?\fB\-novariables\fR? \fIstring\fR
.BE
-
.SH DESCRIPTION
.PP
This command performs variable substitutions, command substitutions,
@@ -36,15 +35,14 @@ For example, if \fB\-nocommands\fR is specified, command substitution
is not performed: open and close brackets are treated as ordinary characters
with no special interpretation.
.PP
-.VS 8.4
Note that the substitution of one kind can include substitution of
-other kinds. For example, even when the \fB-novariables\fR option
+other kinds. For example, even when the \fB\-novariables\fR option
is specified, command substitution is performed without restriction.
This means that any variable substitution necessary to complete the
command substitution will still take place. Likewise, any command
substitution necessary to complete a variable substitution will
-take place, even when \fB-nocommands\fR is specified. See the
-EXAMPLES below.
+take place, even when \fB\-nocommands\fR is specified. See the
+\fBEXAMPLES\fR below.
.PP
If an error occurs during substitution, then \fBsubst\fR will return
that error. If a break exception occurs during command or variable
@@ -56,10 +54,11 @@ will be substituted for that entire command or variable substitution
(as long as it is well-formed Tcl.) If a return exception occurs,
or any other return code is returned during command or variable
substitution, then the returned value is substituted for that
-substitution. See the EXAMPLES below. In this way, all exceptional
-return codes are ``caught'' by \fBsubst\fR. The \fBsubst\fR command
+substitution. See the \fBEXAMPLES\fR below. In this way, all exceptional
+return codes are
+.QW caught
+by \fBsubst\fR. The \fBsubst\fR command
itself will either return an error, or will complete successfully.
-.VE
.SH EXAMPLES
.PP
When it performs its substitutions, \fIsubst\fR does not give any
@@ -69,22 +68,31 @@ command substitutions) so the script
set a 44
\fBsubst\fR {xyz {$a}}
.CE
-returns ``\fBxyz {44}\fR'', not ``\fBxyz {$a}\fR''
-.VS 8.4
+returns
+.QW "\fBxyz {44}\fR" ,
+not
+.QW "\fBxyz {$a}\fR"
and the script
.CS
-set a "p\\} q \\{r"
+set a "p\e} q \e{r"
\fBsubst\fR {xyz {$a}}
.CE
-return ``\fBxyz {p} q {r}\fR'', not ``\fBxyz {p\\} q \\{r}\fR''.
+returns
+.QW "\fBxyz {p} q {r}\fR" ,
+not
+.QW "\fBxyz {p\e} q \e{r}\fR".
.PP
When command substitution is performed, it includes any variable
-substitution necessary to evaluate the script.
+substitution necessary to evaluate the script.
.CS
set a 44
\fBsubst\fR -novariables {$a [format $a]}
.CE
-returns ``\fB$a 44\fR'', not ``\fB$a $a\fR''. Similarly, when
+returns
+.QW "\fB$a 44\fR" ,
+not
+.QW "\fB$a $a\fR" .
+Similarly, when
variable substitution is performed, it includes any command
substitution necessary to retrieve the value of the variable.
.CS
@@ -92,7 +100,10 @@ proc b {} {return c}
array set a {c c [b] tricky}
\fBsubst\fR -nocommands {[b] $a([b])}
.CE
-returns ``\fB[b] c\fR'', not ``\fB[b] tricky\fR''.
+returns
+.QW "\fB[b] c\fR" ,
+not
+.QW "\fB[b] tricky\fR" .
.PP
The continue and break exceptions allow command substitutions to
prevent substitution of the rest of the command substitution and the
@@ -101,25 +112,36 @@ when processing text using \fIsubst\fR. For example, the script
.CS
\fBsubst\fR {abc,[break],def}
.CE
-returns ``\fBabc,\fR'', not ``\fBabc,,def\fR'' and the script
+returns
+.QW \fBabc,\fR ,
+not
+.QW \fBabc,,def\fR
+and the script
.CS
-\fBsubst\fR {abc,[continue;expr 1+2],def}
+\fBsubst\fR {abc,[continue;expr {1+2}],def}
.CE
-returns ``\fBabc,,def\fR'', not ``\fBabc,3,def\fR''.
+returns
+.QW \fBabc,,def\fR ,
+not
+.QW \fBabc,3,def\fR .
.PP
Other exceptional return codes substitute the returned value
.CS
-\fBsubst\fR {abc,[return foo;expr 1+2],def}
+\fBsubst\fR {abc,[return foo;expr {1+2}],def}
.CE
-returns ``\fBabc,foo,def\fR'', not ``\fBabc,3,def\fR'' and
+returns
+.QW \fBabc,foo,def\fR ,
+not
+.QW \fBabc,3,def\fR
+and
.CS
-\fBsubst\fR {abc,[return -code 10 foo;expr 1+2],def}
+\fBsubst\fR {abc,[return -code 10 foo;expr {1+2}],def}
.CE
-also returns ``\fBabc,foo,def\fR'', not ``\fBabc,3,def\fR''.
-.VE
-
+also returns
+.QW \fBabc,foo,def\fR ,
+not
+.QW \fBabc,3,def\fR .
.SH "SEE ALSO"
Tcl(n), eval(n), break(n), continue(n)
-
.SH KEYWORDS
backslash substitution, command substitution, variable substitution