From 84adefa331c4159d432d22840663c38f155cd4c1 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Fri, 20 Nov 2009 14:54:40 +0000 Subject: The R13B03 release. --- lib/erl_interface/doc/src/erl_error.xml | 136 ++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 lib/erl_interface/doc/src/erl_error.xml (limited to 'lib/erl_interface/doc/src/erl_error.xml') diff --git a/lib/erl_interface/doc/src/erl_error.xml b/lib/erl_interface/doc/src/erl_error.xml new file mode 100644 index 0000000000..4a3f34fac7 --- /dev/null +++ b/lib/erl_interface/doc/src/erl_error.xml @@ -0,0 +1,136 @@ + + + + +
+ + 19962009 + Ericsson AB. All Rights Reserved. + + + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + + + erl_error + Torbjörn Törnkvist + Torbjörn Törnkvist + + Bjarne Däcker + Torbjörn Törnkvist + 961014 + A + erl_error.sgml +
+ erl_error + Error Print Routines + +

This module contains some error printing routines taken + from Advanced Programming in the UNIX Environment + by W. Richard Stevens.

+

These functions are all called in the same manner as + , i.e. with a string containing format specifiers + followed by a list of corresponding arguments. All output from + these functions is to .

+ + + + voiderl_err_msg(FormatStr, ... ) + Non-fatal error, and not system call error + + const char *FormatStr; + + +

The message provided by the caller is printed. This + function is simply a wrapper for .

+ + + + voiderl_err_quit(FormatStr, ... ) + Fatal error, but not system call error + + const char *FormatStr; + + +

Use this function when a fatal error has occurred that + is not due to a system call. The message provided by the + caller is printed and the process terminates with an exit + value of 1. The function does not return.

+ + + + voiderl_err_ret(FormatStr, ... ) + Non-fatal system call error + + const char *FormatStr; + + +

Use this function after a failed system call. The message + provided by the caller is printed followed by a string + describing the reason for failure.

+ + + + voiderl_err_sys(FormatStr, ... ) + Fatal system call error + + const char *FormatStr; + + +

Use this function after a failed system call. The message + provided by the caller is printed followed by a string + describing the reason for failure, and the process + terminates with an exit value of 1. The function does not + return.

+ + + + +
+ Error Reporting +

Most functions in erl_interface report failures to the caller by + returning some otherwise meaningless value (typically + or a negative number). As this only tells you that things did not + go well, you will have to examine the error code in + if you want to find out more about the failure.

+
+ + + volatile interl_errno + The variable contains the erl_interface error number. You can change the value if you wish. + +

is initially (at program startup) zero and + is then set by many erl_interface functions on failure to a + non-zero error code to indicate what kind of error it + encountered. A successful function call might change + (by calling some other function that + fails), but no function will ever set it to zero. This means + that you cannot use to see if a + function call failed. Instead, each function reports failure + in its own way (usually by returning a negative number or + ), in which case you can examine + for details.

+

uses the error codes defined in your + system's ]]>.

+ +

Actually, is a "modifiable lvalue" (just + like ISO C defines to be) rather than a + variable. This means it might be implemented as a macro + (expanding to, e.g., ). For reasons of + thread- (or task-)safety, this is exactly what we do on most + platforms.

+ + + + + + -- cgit v1.2.3