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'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
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.so man.macros
.TH Tcl_FindExecutable 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_FindExecutable, Tcl_GetNameOfExecutable \- identify or return the name of the binary file containing the application
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
Tcl_Interp *
\fBTcl_FindExecutable\fR(\fIargv0\fR)
.sp
const char *
\fBTcl_GetNameOfExecutable\fR()
.SH ARGUMENTS
.AS void *argv0
.AP void *argv0 in
The first command-line argument to the program, which gives the
application's name.
.BE

.SH DESCRIPTION
.PP
The \fBTcl_FindExecutable\fR procedure computes the full path name of
the executable file from which the application was invoked and saves
it for Tcl's internal use.
The executable's path name is needed for several purposes in
Tcl.  For example, it is needed on some platforms in the
implementation of the \fBload\fR command.
It is also returned by the \fBinfo nameofexecutable\fR command.
.PP
The \fBTcl_FindExecutable\fR procedure returns a pointer which
can be used by \fBTcl_InitStubs\fR to initialize the stubs
table, without realy needing a real Tcl_Interp structure.
.PP
On UNIX platforms this procedure is typically invoked as the very
first thing in the application's main program;  it must be passed
\fIargv[0]\fR as its argument.  It is important not to change the
working directory before the invocation.
\fBTcl_FindExecutable\fR uses \fIargv0\fR
along with the \fBPATH\fR environment variable to find the
application's executable, if possible.  If it fails to find
the binary, then future calls to \fBinfo nameofexecutable\fR
will return an empty string.
.PP
On Windows platforms this procedure is typically invoked as the very
first thing in the application's main program as well; Its \fIargv[0]\fR
argument is only used to indicate whether the executable has a stderr
channel (any non-null value) or not (the value null). If \fBTcl_SetPanicProc\fR
is never called and no debugger is running, this determines whether
the panic message is sent to stderr or to a standard system dialog.
.PP
\fBTcl_GetNameOfExecutable\fR simply returns a pointer to the
internal full path name of the executable file as computed by
\fBTcl_FindExecutable\fR.  This procedure call is the C API
equivalent to the \fBinfo nameofexecutable\fR command.  NULL
is returned if the internal full path name has not been
computed or unknown.

.SH KEYWORDS
binary, executable file
