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+'\"
+'\" Copyright (c) 1990-1992 The Regents of the University of California.
+'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
+'\"
+'\" See the file "license.terms" for information on usage and redistribution
+'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+'\"
+'\" SCCS: @(#) ParseArgv.3 1.17 97/10/31 12:58:44
+'\"
+.so man.macros
+.TH Tk_ParseArgv 3 "" Tk "Tk Library Procedures"
+.BS
+.SH NAME
+Tk_ParseArgv \- process command-line options
+.SH SYNOPSIS
+.nf
+\fB#include <tk.h>\fR
+.sp
+int
+\fBTk_ParseArgv\fR(\fIinterp, tkwin, argcPtr, argv, argTable, flags\fR)
+.SH ARGUMENTS
+.AS Tk_ArgvInfo *argTable
+.AP Tcl_Interp *interp in
+Interpreter to use for returning error messages.
+.AP Tk_Window tkwin in
+Window to use when arguments specify Tk options. If NULL, then
+no Tk options will be processed.
+.AP int argcPtr in/out
+Pointer to number of arguments in argv; gets modified to hold
+number of unprocessed arguments that remain after the call.
+.AP char **argv in/out
+Command line arguments passed to main program. Modified to
+hold unprocessed arguments that remain after the call.
+.AP Tk_ArgvInfo *argTable in
+Array of argument descriptors, terminated by element with
+type TK_ARGV_END.
+.AP int flags in
+If non-zero, then it specifies one or more flags that control the
+parsing of arguments. Different flags may be OR'ed together.
+The flags currently defined are TK_ARGV_DONT_SKIP_FIRST_ARG,
+TK_ARGV_NO_ABBREV, TK_ARGV_NO_LEFTOVERS, and TK_ARGV_NO_DEFAULTS.
+.BE
+.SH DESCRIPTION
+.PP
+\fBTk_ParseArgv\fR processes an array of command-line arguments according
+to a table describing the kinds of arguments that are expected.
+Each of the arguments in \fIargv\fR is processed in turn: if it matches
+one of the entries in \fIargTable\fR, the argument is processed
+according to that entry and discarded. The arguments that do not
+match anything in \fIargTable\fR are copied down to the beginning
+of \fIargv\fR (retaining their original order) and returned to
+the caller. At the end of the call
+\fBTk_ParseArgv\fR sets \fI*argcPtr\fR to hold the number of
+arguments that are left in \fIargv\fR, and \fIargv[*argcPtr]\fR
+will hold the value NULL. Normally, \fBTk_ParseArgv\fR
+assumes that \fIargv[0]\fR is a command name, so it is treated like
+an argument that doesn't match \fIargTable\fR and returned to the
+caller; however, if the TK_ARGV_DONT_SKIP_FIRST_ARG bit is set in
+\fIflags\fR then \fIargv[0]\fR will be processed just like the other
+elements of \fIargv\fR.
+.PP
+\fBTk_ParseArgv\fR normally returns the value TCL_OK. If an error
+occurs while parsing the arguments, then TCL_ERROR is returned and
+\fBTk_ParseArgv\fR will leave an error message in \fIinterp->result\fR
+in the standard Tcl fashion. In
+the event of an error return, \fI*argvPtr\fR will not have been
+modified, but \fIargv\fR could have been partially modified. The
+possible causes of errors are explained below.
+.PP
+The \fIargTable\fR array specifies the kinds of arguments that are
+expected; each of its entries has the following structure:
+.CS
+typedef struct {
+ char *\fIkey\fR;
+ int \fItype\fR;
+ char *\fIsrc\fR;
+ char *\fIdst\fR;
+ char *\fIhelp\fR;
+} Tk_ArgvInfo;
+.CE
+The \fIkey\fR field is a string such as ``\-display'' or ``\-bg''
+that is compared with the values in \fIargv\fR. \fIType\fR
+indicates how to process an argument that matches \fIkey\fR
+(more on this below). \fISrc\fR and \fIdst\fR are additional
+values used in processing the argument. Their exact usage
+depends on \fItype\fR, but typically \fIsrc\fR indicates
+a value and \fIdst\fR indicates where to store the
+value. The \fBchar *\fR declarations for \fIsrc\fR and \fIdst\fR
+are placeholders: the actual types may be different. Lastly,
+\fIhelp\fR is a string giving a brief description
+of this option; this string is printed when users ask for help
+about command-line options.
+.PP
+When processing an argument in \fIargv\fR, \fBTk_ParseArgv\fR
+compares the argument to each of the \fIkey\fR's in \fIargTable\fR.
+\fBTk_ParseArgv\fR selects the first specifier whose \fIkey\fR matches
+the argument exactly, if such a specifier exists. Otherwise
+\fBTk_ParseArgv\fR selects a specifier for which the argument
+is a unique abbreviation. If the argument is a unique abbreviation
+for more than one specifier, then an error is returned. If there
+is no matching entry in \fIargTable\fR, then the argument is
+skipped and returned to the caller.
+.PP
+Once a matching argument specifier is found, \fBTk_ParseArgv\fR
+processes the argument according to the \fItype\fR field of the
+specifier. The argument that matched \fIkey\fR is called ``the matching
+argument'' in the descriptions below. As part of the processing,
+\fBTk_ParseArgv\fR may also use the next argument in \fIargv\fR
+after the matching argument, which is called ``the following
+argument''. The legal values for \fItype\fR, and the processing
+that they cause, are as follows:
+.TP
+\fBTK_ARGV_END\fR
+Marks the end of the table. The last entry in \fIargTable\fR
+must have this type; all of its other fields are ignored and it
+will never match any arguments.
+.TP
+\fBTK_ARGV_CONSTANT\fR
+\fISrc\fR is treated as an integer and \fIdst\fR is treated
+as a pointer to an integer. \fISrc\fR is stored at \fI*dst\fR.
+The matching argument is discarded.
+.TP
+\fBTK_ARGV_INT\fR
+The following argument must contain an
+integer string in the format accepted by \fBstrtol\fR (e.g. ``0''
+and ``0x'' prefixes may be used to specify octal or hexadecimal
+numbers, respectively). \fIDst\fR is treated as a pointer to an
+integer; the following argument is converted to an integer value
+and stored at \fI*dst\fR. \fISrc\fR is ignored. The matching
+and following arguments are discarded from \fIargv\fR.
+.TP
+\fBTK_ARGV_FLOAT\fR
+The following argument must contain a floating-point number in
+the format accepted by \fBstrtol\fR.
+\fIDst\fR is treated as the address of an double-precision
+floating point value; the following argument is converted to a
+double-precision value and stored at \fI*dst\fR. The matching
+and following arguments are discarded from \fIargv\fR.
+.TP
+\fBTK_ARGV_STRING\fR
+In this form, \fIdst\fR is treated as a pointer to a (char *);
+\fBTk_ParseArgv\fR stores at \fI*dst\fR a pointer to the following
+argument, and discards the matching and following arguments from
+\fIargv\fR. \fISrc\fR is ignored.
+.TP
+\fBTK_ARGV_UID\fR
+This form is similar to TK_ARGV_STRING, except that the argument
+is turned into a Tk_Uid by calling \fBTk_GetUid\fR.
+\fIDst\fR is treated as a pointer to a
+Tk_Uid; \fBTk_ParseArgv\fR stores at \fI*dst\fR the Tk_Uid
+corresponding to the following
+argument, and discards the matching and following arguments from
+\fIargv\fR. \fISrc\fR is ignored.
+.TP
+\fBTK_ARGV_CONST_OPTION\fR
+This form causes a Tk option to be set (as if the \fBoption\fR
+command had been invoked). The \fIsrc\fR field is treated as a
+pointer to a string giving the value of an option, and \fIdst\fR
+is treated as a pointer to the name of the option. The matching
+argument is discarded. If \fItkwin\fR is NULL, then argument
+specifiers of this type are ignored (as if they did not exist).
+.TP
+\fBTK_ARGV_OPTION_VALUE\fR
+This form is similar to TK_ARGV_CONST_OPTION, except that the
+value of the option is taken from the following argument instead
+of from \fIsrc\fR. \fIDst\fR is used as the name of the option.
+\fISrc\fR is ignored. The matching and following arguments
+are discarded. If \fItkwin\fR is NULL, then argument
+specifiers of this type are ignored (as if they did not exist).
+.TP
+\fBTK_ARGV_OPTION_NAME_VALUE\fR
+In this case the following argument is taken as the name of a Tk
+option and the argument after that is taken as the value for that
+option. Both \fIsrc\fR and \fIdst\fR are ignored. All three
+arguments are discarded from \fIargv\fR. If \fItkwin\fR is NULL,
+then argument
+specifiers of this type are ignored (as if they did not exist).
+.TP
+\fBTK_ARGV_HELP\fR
+When this kind of option is encountered, \fBTk_ParseArgv\fR uses the
+\fIhelp\fR fields of \fIargTable\fR to format a message describing
+all the valid arguments. The message is placed in \fIinterp->result\fR
+and \fBTk_ParseArgv\fR returns TCL_ERROR. When this happens, the
+caller normally prints the help message and aborts. If the \fIkey\fR
+field of a TK_ARGV_HELP specifier is NULL, then the specifier will
+never match any arguments; in this case the specifier simply provides
+extra documentation, which will be included when some other
+TK_ARGV_HELP entry causes help information to be returned.
+.TP
+\fBTK_ARGV_REST\fR
+This option is used by programs or commands that allow the last
+several of their options to be the name and/or options for some
+other program. If a \fBTK_ARGV_REST\fR argument is found, then
+\fBTk_ParseArgv\fR doesn't process any
+of the remaining arguments; it returns them all at
+the beginning of \fIargv\fR (along with any other unprocessed arguments).
+In addition, \fBTk_ParseArgv\fR treats \fIdst\fR as the address of an
+integer value, and stores at \fI*dst\fR the index of the first of the
+\fBTK_ARGV_REST\fR options in the returned \fIargv\fR. This allows the
+program to distinguish the \fBTK_ARGV_REST\fR options from other
+unprocessed options that preceded the \fBTK_ARGV_REST\fR.
+.TP
+\fBTK_ARGV_FUNC\fR
+For this kind of argument, \fIsrc\fR is treated as the address of
+a procedure, which is invoked to process the following argument.
+The procedure should have the following structure:
+.RS
+.CS
+int
+\fIfunc\fR(\fIdst\fR, \fIkey\fR, \fInextArg\fR)
+ char *\fIdst\fR;
+ char *\fIkey\fR;
+ char *\fInextArg\fR;
+{
+}
+.CE
+The \fIdst\fR and \fIkey\fR parameters will contain the
+corresponding fields from the \fIargTable\fR entry, and
+\fInextArg\fR will point to the following argument from \fIargv\fR
+(or NULL if there aren't any more arguments left in \fIargv\fR).
+If \fIfunc\fR uses \fInextArg\fR (so that
+\fBTk_ParseArgv\fR should discard it), then it should return 1. Otherwise it
+should return 0 and \fBTkParseArgv\fR will process the following
+argument in the normal fashion. In either event the matching argument
+is discarded.
+.RE
+.TP
+\fBTK_ARGV_GENFUNC\fR
+This form provides a more general procedural escape. It treats
+\fIsrc\fR as the address of a procedure, and passes that procedure
+all of the remaining arguments. The procedure should have the following
+form:
+.RS
+.CS
+int
+\fIgenfunc\fR(dst, interp, key, argc, argv)
+ char *\fIdst\fR;
+ Tcl_Interp *\fIinterp\fR;
+ char *\fIkey\fR;
+ int \fIargc\fR;
+ char **\fIargv\fR;
+{
+}
+.CE
+The \fIdst\fR and \fIkey\fR parameters will contain the
+corresponding fields from the \fIargTable\fR entry. \fIInterp\fR
+will be the same as the \fIinterp\fR argument to \fBTcl_ParseArgv\fR.
+\fIArgc\fR and \fIargv\fR refer to all of the options after the
+matching one. \fIGenfunc\fR should behave in a fashion similar
+to \fBTk_ParseArgv\fR: parse as many of the remaining arguments as it can,
+then return any that are left by compacting them to the beginning of
+\fIargv\fR (starting at \fIargv\fR[0]). \fIGenfunc\fR
+should return a count of how many arguments are left in \fIargv\fR;
+\fBTk_ParseArgv\fR will process them. If \fIgenfunc\fR encounters
+an error then it should leave an error message in \fIinterp->result\fR,
+in the usual Tcl fashion, and return -1; when this happens
+\fBTk_ParseArgv\fR will abort its processing and return TCL_ERROR.
+.RE
+
+.SH "FLAGS"
+.TP
+\fBTK_ARGV_DONT_SKIP_FIRST_ARG\fR
+\fBTk_ParseArgv\fR normally treats \fIargv[0]\fR as a program
+or command name, and returns it to the caller just as if it
+hadn't matched \fIargTable\fR. If this flag is given, then
+\fIargv[0]\fR is not given special treatment.
+.TP
+\fBTK_ARGV_NO_ABBREV\fR
+Normally, \fBTk_ParseArgv\fR accepts unique abbreviations for
+\fIkey\fR values in \fIargTable\fR. If this flag is given then
+only exact matches will be acceptable.
+.TP
+\fBTK_ARGV_NO_LEFTOVERS\fR
+Normally, \fBTk_ParseArgv\fR returns unrecognized arguments to the
+caller. If this bit is set in \fIflags\fR then \fBTk_ParseArgv\fR
+will return an error if it encounters any argument that doesn't
+match \fIargTable\fR. The only exception to this rule is \fIargv[0]\fR,
+which will be returned to the caller with no errors as
+long as TK_ARGV_DONT_SKIP_FIRST_ARG isn't specified.
+.TP
+\fBTK_ARGV_NO_DEFAULTS\fR
+Normally, \fBTk_ParseArgv\fR searches an internal table of
+standard argument specifiers in addition to \fIargTable\fR. If
+this bit is set in \fIflags\fR, then \fBTk_ParseArgv\fR will
+use only \fIargTable\fR and not its default table.
+
+.SH EXAMPLE
+.PP
+Here is an example definition of an \fIargTable\fR and
+some sample command lines that use the options. Note the effect
+on \fIargc\fR and \fIargv\fR; arguments processed by \fBTk_ParseArgv\fR
+are eliminated from \fIargv\fR, and \fIargc\fR
+is updated to reflect reduced number of arguments.
+.CS
+/*
+ * Define and set default values for globals.
+ */
+int debugFlag = 0;
+int numReps = 100;
+char defaultFileName[] = "out";
+char *fileName = defaultFileName;
+Boolean exec = FALSE;
+
+/*
+ * Define option descriptions.
+ */
+Tk_ArgvInfo argTable[] = {
+ {"-X", TK_ARGV_CONSTANT, (char *) 1, (char *) &debugFlag,
+ "Turn on debugging printfs"},
+ {"-N", TK_ARGV_INT, (char *) NULL, (char *) &numReps,
+ "Number of repetitions"},
+ {"-of", TK_ARGV_STRING, (char *) NULL, (char *) &fileName,
+ "Name of file for output"},
+ {"x", TK_ARGV_REST, (char *) NULL, (char *) &exec,
+ "File to exec, followed by any arguments (must be last argument)."},
+ {(char *) NULL, TK_ARGV_END, (char *) NULL, (char *) NULL,
+ (char *) NULL}
+};
+
+main(argc, argv)
+ int argc;
+ char *argv[];
+{
+ \&...
+
+ if (Tk_ParseArgv(interp, tkwin, &argc, argv, argTable, 0) != TCL_OK) {
+ fprintf(stderr, "%s\en", interp->result);
+ exit(1);
+ }
+
+ /*
+ * Remainder of the program.
+ */
+}
+.CE
+.PP
+Note that default values can be assigned to variables named in
+\fIargTable\fR: the variables will only be overwritten if the
+particular arguments are present in \fIargv\fR.
+Here are some example command lines and their effects.
+.CS
+prog -N 200 infile # just sets the numReps variable to 200
+prog -of out200 infile # sets fileName to reference "out200"
+prog -XN 10 infile # sets the debug flag, also sets numReps
+.CE
+In all of the above examples, \fIargc\fR will be set by \fBTk_ParseArgv\fR to 2,
+\fIargv\fR[0] will be ``prog'', \fIargv\fR[1] will be ``infile'',
+and \fIargv\fR[2] will be NULL.
+
+.SH KEYWORDS
+arguments, command line, options