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a6824debbc
Changed calc_errno a global int variable so that is may be directly accessed by libcalc users. Further improve help files for help/errno, help/error, help/newerror, help/stoponerror and help/strerror by adding to documentation of the calc error code system as well as libcalc interface where applicable. Changed #define E_USERDEF to #define E__USERDEF. Removed use of E_USERDEF, E__BASE, E__COUNT, and E__HIGHEST from custom/c_sysinfo because the c_sysinfo is just a demo and this will simplify the custom/Makefile. The include file calcerr.h is now the errsym.h include file. The calcerr.tbl has been replaced by errtbl.c and errtbl.h. The calcerr_c.awk, calcerr_c.sed, calcerr_h.awk, and calcerr_h.sed files are now obsolete and have been removed. The calcerr.c and calcerr.h now obsolete and are no longer built. The calc computation error codes, symbols and messages are now in a error_table[] array of struct errtbl. An E_STRING is a string corresponds to an error code #define. For example, the E_STRING for the calc error E_STRCAT, is the string "E_STRING". An E_STRING must now match the regular expression: "^E_[A-Z0-9_]+$". The old array error_table[] of error message strings has been replaced by a new error_table[] array of struct errtbl. The struct errtbl array holds calc errnum error codes, the related E_STRING symbol as a string, and the original related error message. To add new computation error codes, add them near the bottom of the error_table[] array, just before the NULL entry. The ./errcode utility, when run, will verify the consistency of the error_table[] array. The Makefile uses ./errcode -e to generate the contents of help/errorcodes file. The help errorcodes now prints information from the new cstruct errtbl error_table[] array. The help/errorcodes.hdr and help/errorcodes.sed files are now obsolete and have been removed. The Makefile uses ./errcode -d to generate the contents of the errsym.h include file. Updated .gitignore and trailblank to support the above changes.
99 lines
3.4 KiB
Plaintext
99 lines
3.4 KiB
Plaintext
NAME
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errno - return or set a the global calc_errno value
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SYNOPSIS
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errno([errnum | "E_STRING"])
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TYPES
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errnum integer
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E_STRING string
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return integer
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DESCRIPTION
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Whenever an operation or evaluation of function returns an error-value,
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the numerical code for that value is stored as "global calc_errno value".
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The term "global calc_errno value" is an internal calc state.
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This is NOT a calc variable called calc_errno.
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NOTE:
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The errno() builtin should not be confused with the errno
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used by libc in C. The range of errnum extend beyond the
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C's libc errno. See help error for information on the mean
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of various errnum ranges.
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Unlike error() calling errno() does NOT increment the global
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calc error count (see help errcount).
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errno() returns the current value of "global calc_errno value".
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Unlike error() calling errno() does NOT increment the global
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calc error count (see help errcount).
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errno(errnum) sets "global calc_errno value" to the value errnum
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and returns its previous value. Unlike error(errnum) calling
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errno(errnum) does NOT increment the global calc error count
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(see help errcount).
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To detect whether an error occurs during some sequence of operations,
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one may immediately before that sequence set the stored error-number
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to zero by errno(0), and then after the operations, whether or not
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an error has occurred will be indicated by errno() being nonzero or
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zero. If a non-zero value is returned, that value will be the code
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for the most recent error encountered.
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The default argument for the functions error() and strerror() is the
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currently stored error-number; in particular, if no error-value has
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been returned after the last errno(0), strerror() will return
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"No error".
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EXAMPLE
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; ## Assuming there is no file with name "not_a_file"
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; errcount(0),; errmax(20),;
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; print errcount(), errmax()
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0 20
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; badfile = fopen("not_a_file", "r")
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; print errcount(), errno(), strerror()
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1 2 No such file or directory
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; a = 1/0
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; print errcount(), errno(), strerror()
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2 10001 Division by zero
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LIMITS
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0 <= errnum <= 32767
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LINK LIBRARY
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int calc_errno; /* global calc_errno value */
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E_STRING is C string matching the regular expression: "^E_[A-Z0-9_]+$"
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SEE ALSO
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errmax, errcount, error, strerror, iserror, newerror, errorcodes,
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stoponerror
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## Copyright (C) 1999-2006,2021,2023 Landon Curt Noll
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##
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## Calc is open software; you can redistribute it and/or modify it under
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## the terms of the version 2.1 of the GNU Lesser General Public License
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## as published by the Free Software Foundation.
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##
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## Calc is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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## Public License for more details.
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##
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## A copy of version 2.1 of the GNU Lesser General Public License is
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## distributed with calc under the filename COPYING-LGPL. You should have
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## received a copy with calc; if not, write to Free Software Foundation, Inc.
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## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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##
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## Under source code control: 1994/10/27 03:05:08
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## File existed as early as: 1994
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##
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## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
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## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
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