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author | William Joye <wjoye@cfa.harvard.edu> | 2017-09-22 18:51:12 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2017-09-22 18:51:12 (GMT) |
commit | 3fa8e6dc88e8041b6cb88d1b1e9c05676d3346b7 (patch) | |
tree | 69afbb41089c8358615879f7cd3c4cf7997f4c7e /tcl8.6/doc/subst.n | |
parent | a0e17db23c0fd7c771c0afce8cce350c98f90b02 (diff) | |
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update to tcl/tk 8.6.7
Diffstat (limited to 'tcl8.6/doc/subst.n')
-rw-r--r-- | tcl8.6/doc/subst.n | 164 |
1 files changed, 0 insertions, 164 deletions
diff --git a/tcl8.6/doc/subst.n b/tcl8.6/doc/subst.n deleted file mode 100644 index 4518140..0000000 --- a/tcl8.6/doc/subst.n +++ /dev/null @@ -1,164 +0,0 @@ -'\" -'\" Copyright (c) 1994 The Regents of the University of California. -'\" Copyright (c) 1994-1996 Sun Microsystems, Inc. -'\" Copyright (c) 2001 Donal K. Fellows -'\" -'\" See the file "license.terms" for information on usage and redistribution -'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -.TH subst n 7.4 Tcl "Tcl Built-In Commands" -.so man.macros -.BS -'\" Note: do not modify the .SH NAME line immediately below! -.SH NAME -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, -and backslash substitutions on its \fIstring\fR argument and -returns the fully-substituted result. -The substitutions are performed in exactly the same way as for -Tcl commands. -As a result, the \fIstring\fR argument is actually substituted twice, -once by the Tcl parser in the usual fashion for Tcl commands, and -again by the \fIsubst\fR command. -.PP -If any of the \fB\-nobackslashes\fR, \fB\-nocommands\fR, or -\fB\-novariables\fR are specified, then the corresponding substitutions -are not performed. -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 -Note that the substitution of one kind can include substitution of -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 -\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 -substitution, the result of the whole substitution will be the -string (as substituted) up to the start of the substitution that -raised the exception. If a continue exception occurs during the -evaluation of a command or variable substitution, an empty string -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 \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. -.SH EXAMPLES -.PP -When it performs its substitutions, \fIsubst\fR does not give any -special treatment to double quotes or curly braces (except within -command substitutions) so the script -.PP -.CS -set a 44 -\fBsubst\fR {xyz {$a}} -.CE -.PP -returns -.QW "\fBxyz {44}\fR" , -not -.QW "\fBxyz {$a}\fR" -and the script -.PP -.CS -set a "p\e} q \e{r" -\fBsubst\fR {xyz {$a}} -.CE -.PP -returns -.QW "\fBxyz {p} q {r}\fR" , -not -.QW "\fBxyz {p\e} q \e{r}\fR". -.PP -When command substitution is performed, it includes any variable -substitution necessary to evaluate the script. -.PP -.CS -set a 44 -\fBsubst\fR -novariables {$a [format $a]} -.CE -.PP -returns -.QW "\fB$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. -.PP -.CS -proc b {} {return c} -array set a {c c [b] tricky} -\fBsubst\fR -nocommands {[b] $a([b])} -.CE -.PP -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 -rest of \fIstring\fR respectively, giving script authors more options -when processing text using \fIsubst\fR. For example, the script -.PP -.CS -\fBsubst\fR {abc,[break],def} -.CE -.PP -returns -.QW \fBabc,\fR , -not -.QW \fBabc,,def\fR -and the script -.PP -.CS -\fBsubst\fR {abc,[continue;expr {1+2}],def} -.CE -.PP -returns -.QW \fBabc,,def\fR , -not -.QW \fBabc,3,def\fR . -.PP -Other exceptional return codes substitute the returned value -.PP -.CS -\fBsubst\fR {abc,[return foo;expr {1+2}],def} -.CE -.PP -returns -.QW \fBabc,foo,def\fR , -not -.QW \fBabc,3,def\fR -and -.PP -.CS -\fBsubst\fR {abc,[return -code 10 foo;expr {1+2}],def} -.CE -.PP -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, quoting, substitution, variable substitution -.\" Local Variables: -.\" mode: nroff -.\" End: |