diff options
Diffstat (limited to 'doc/tclvars.n')
| -rw-r--r-- | doc/tclvars.n | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/doc/tclvars.n b/doc/tclvars.n index d664784..4317436 100644 --- a/doc/tclvars.n +++ b/doc/tclvars.n @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: tclvars.n,v 1.30 2007/10/28 14:17:40 dkf Exp $ +'\" RCS: @(#) $Id: tclvars.n,v 1.31 2007/10/29 01:42:19 dkf Exp $ '\" .so man.macros .TH tclvars n 8.0 Tcl "Tcl Built-In Commands" @@ -14,7 +14,6 @@ .SH NAME tclvars \- Variables used by Tcl .BE - .SH DESCRIPTION .PP The following global variables are created and managed automatically @@ -27,7 +26,7 @@ whose elements are the environment variables for the process. Reading an element will return the value of the corresponding environment variable. Setting an element of the array will modify the corresponding -environment variable or create a new one if it doesn't already +environment variable or create a new one if it does not already exist. Unsetting an element of \fBenv\fR will remove the corresponding environment variable. @@ -39,13 +38,16 @@ variables. .RS Under Windows, the environment variables PATH and COMSPEC in any capitalization are converted automatically to upper case. For instance, the -PATH variable could be exported by the operating system as ``path'', -``Path'', ``PaTh'', etc., causing otherwise simple Tcl code to have to +PATH variable could be exported by the operating system as +.QW path , +.QW Path , +.QW PaTh , +etc., causing otherwise simple Tcl code to have to support many special cases. All other environment variables inherited by Tcl are left unmodified. Setting an env array variable to blank is the same as unsetting it as this is the behavior of the underlying Windows OS. It should be noted that relying on an existing and empty environment variable -won't work on windows and is discouraged for cross-platform usage. +will not work on Windows and is discouraged for cross-platform usage. .RE .TP \fBerrorCode\fR @@ -78,7 +80,8 @@ The \fIsigName\fR element will be the symbolic name of the signal that caused the process to terminate; it will be one of the names from the include file signal.h, such as \fBSIGPIPE\fR. The \fImsg\fR element will be a short human-readable message -describing the signal, such as ``write on pipe with no readers'' +describing the signal, such as +.QW "write on pipe with no readers" for \fBSIGPIPE\fR. .TP \fBCHILDSTATUS\fI pid code\fR @@ -95,7 +98,8 @@ The \fIsigName\fR element will be the symbolic name of the signal that caused the process to suspend; this will be one of the names from the include file signal.h, such as \fBSIGTTIN\fR. The \fImsg\fR element will be a short human-readable message -describing the signal, such as ``background tty read'' +describing the signal, such as +.QW "background tty read" for \fBSIGTTIN\fR. .TP \fBNONE\fR @@ -113,13 +117,14 @@ of the error that occurred, such as \fBENOENT\fR; this will be one of the values defined in the include file errno.h. The \fImsg\fR element will be a human-readable message corresponding to \fIerrName\fR, such as -``no such file or directory'' for the \fBENOENT\fR case. +"no such file or directory" +for the \fBENOENT\fR case. .PP To set the \fB-errorcode\fR return option, applications should use library procedures such as \fBTcl_SetObjErrorCode\fR, \fBTcl_SetReturnOptions\fR, and \fBTcl_PosixError\fR, or they may invoke the \fB-errorcode\fR option of the \fBreturn\fR command. -If one of these methods hasn't been used, then the Tcl +If one of these methods has not been used, then the Tcl interpreter will reset the variable to \fBNONE\fR after the next error. .RE @@ -149,7 +154,7 @@ is created by searching several different directories until one is found that contains an appropriate Tcl startup script. If the \fBTCL_LIBRARY\fR environment variable exists, then the directory it names is checked first. -If \fBTCL_LIBRARY\fR isn't set or doesn't refer to an appropriate +If \fBTCL_LIBRARY\fR is not set or doesn't refer to an appropriate directory, then Tcl checks several other directories based on a compiled-in default location, the location of the binary containing the application, and the current working directory. @@ -184,7 +189,7 @@ This is an associative array whose elements contain information about the platform on which the application is running, such as the name of the operating system, its current release number, and the machine's instruction set. The elements listed below will always -be defined, but they may have empty strings as values if Tcl couldn't +be defined, but they may have empty strings as values if Tcl could not retrieve any relevant information. In addition, extensions and applications may add additional values to the array. The predefined elements are: @@ -263,7 +268,9 @@ binary number. .VE 8.5 .PP .RS -17 digits is ``perfect'' for IEEE floating-point in that it allows +17 digits is +.QW perfect +for IEEE floating-point in that it allows double-precision values to be converted to strings and back to binary with no loss of information. However, using 17 digits prevents any rounding, which produces longer, less intuitive results. For example, @@ -334,7 +341,9 @@ This variable and functionality only exist if .TP \fBtcl_wordchars\fR The value of this variable is a regular expression that can be set to -control what are considered ``word'' characters, for instances like +control what are considered +.QW word +characters, for instances like selecting a word by double-clicking in text in Tk. It is platform dependent. On Windows, it defaults to \fB\eS\fR, meaning anything but a Unicode space character. Otherwise it defaults to \fB\ew\fR, @@ -342,7 +351,9 @@ which is any Unicode word character (number, letter, or underscore). .TP \fBtcl_nonwordchars\fR The value of this variable is a regular expression that can be set to -control what are considered ``non-word'' characters, for instances like +control what are considered +.QW non-word +characters, for instances like selecting a word by double-clicking in text in Tk. It is platform dependent. On Windows, it defaults to \fB\es\fR, meaning any Unicode space character. Otherwise it defaults to \fB\eW\fR, which is anything but a @@ -383,9 +394,7 @@ variable: \fBgeometry\fR If set, contains the user-supplied geometry specification to use for the main Tk window. - .SH "SEE ALSO" eval(n), tclsh(1), wish(1) - .SH KEYWORDS arithmetic, bytecode, compiler, error, environment, POSIX, precision, subprocess, variables |