| 1 | '\" |
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| 2 | '\" Copyright (c) 1996 Sun Microsystems, Inc. |
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| 3 | '\" |
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| 4 | '\" See the file "license.terms" for information on usage and redistribution |
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| 5 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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| 6 | '\" |
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| 7 | '\" RCS: @(#) $Id: SetErrno.3,v 1.9 2007/12/13 15:22:31 dgp Exp $ |
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| 8 | .so man.macros |
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| 9 | .TH Tcl_SetErrno 3 8.3 Tcl "Tcl Library Procedures" |
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| 10 | .BS |
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| 11 | .SH NAME |
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| 12 | Tcl_SetErrno, Tcl_GetErrno, Tcl_ErrnoId, Tcl_ErrnoMsg \- manipulate errno to store and retrieve error codes |
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| 13 | .SH SYNOPSIS |
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| 14 | .nf |
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| 15 | \fB#include <tcl.h>\fR |
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| 16 | .sp |
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| 17 | void |
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| 18 | \fBTcl_SetErrno\fR(\fIerrorCode\fR) |
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| 19 | .sp |
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| 20 | int |
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| 21 | \fBTcl_GetErrno\fR() |
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| 22 | .sp |
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| 23 | const char * |
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| 24 | \fBTcl_ErrnoId\fR() |
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| 25 | .sp |
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| 26 | const char * |
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| 27 | \fBTcl_ErrnoMsg\fR(\fIerrorCode\fR) |
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| 28 | .sp |
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| 29 | .SH ARGUMENTS |
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| 30 | .AS int errorCode |
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| 31 | .AP int errorCode in |
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| 32 | A POSIX error code such as \fBENOENT\fR. |
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| 33 | .BE |
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| 34 | |
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| 35 | .SH DESCRIPTION |
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| 36 | .PP |
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| 37 | \fBTcl_SetErrno\fR and \fBTcl_GetErrno\fR provide portable access |
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| 38 | to the \fBerrno\fR variable, which is used to record a POSIX error |
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| 39 | code after system calls and other operations such as \fBTcl_Gets\fR. |
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| 40 | These procedures are necessary because global variable accesses cannot |
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| 41 | be made across module boundaries on some platforms. |
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| 42 | .PP |
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| 43 | \fBTcl_SetErrno\fR sets the \fBerrno\fR variable to the value of the |
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| 44 | \fIerrorCode\fR argument |
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| 45 | C procedures that wish to return error information to their callers |
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| 46 | via \fBerrno\fR should call \fBTcl_SetErrno\fR rather than setting |
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| 47 | \fBerrno\fR directly. |
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| 48 | .PP |
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| 49 | \fBTcl_GetErrno\fR returns the current value of \fBerrno\fR. |
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| 50 | Procedures wishing to access \fBerrno\fR should call this procedure |
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| 51 | instead of accessing \fBerrno\fR directly. |
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| 52 | .PP |
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| 53 | \fBTcl_ErrnoId\fR and \fBTcl_ErrnoMsg\fR return string |
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| 54 | representations of \fBerrno\fR values. \fBTcl_ErrnoId\fR |
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| 55 | returns a machine-readable textual identifier such as |
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| 56 | .QW EACCES |
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| 57 | that corresponds to the current value of \fBerrno\fR. |
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| 58 | \fBTcl_ErrnoMsg\fR returns a human-readable string such as |
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| 59 | .QW "permission denied" |
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| 60 | that corresponds to the value of its |
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| 61 | \fIerrorCode\fR argument. The \fIerrorCode\fR argument is |
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| 62 | typically the value returned by \fBTcl_GetErrno\fR. |
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| 63 | The strings returned by these functions are |
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| 64 | statically allocated and the caller must not free or modify them. |
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| 65 | |
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| 66 | .SH KEYWORDS |
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| 67 | errno, error code, global variables |
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