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1a898caf3f
NOTE: errstr was renamed to errsym. Added errsym builtin function. The errsym(errnum | "E_STRING") builtin, , when given a valid integer errnum that corresponds to a calc error condition, will return an E_STRING string, AND when given a valid E_STRING string that is associated with a calc error condition, will return errnum integer that corresponds to a calc error condition. Supplying a non-integer numeric errnum code to error(), errno(), strerror(), or errsym() will result in an error.
142 lines
4.9 KiB
Plaintext
142 lines
4.9 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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With errno(errnum) numeric argument:
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For 0 < errnum <= 32767:
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errno(errnum) sets "global calc_errno value" to the value
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errnum and returns its previous value. Unlike error(errnum)
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calling errno(errnum) does NOT increment the global calc
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error count (see help errcount).
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For all other errnum values:
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An error error condition is raised about the valid errnum.
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With errno("E_STRING") string argument:
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If E_STRING is a valid errsym code, then the E_STRING errsym
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is converted into an equivalent errnum and errno is set to errnum.
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If E_STRING is not a valid errsym code, an error error condition
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is raised about the invalid E_STRING.
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For example, these two calls are equivalent:
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errno(10003); /* error 10003 has a E_STRING of "E_ADD" */
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errno("E_ADD"); /* error 10003 has a E_STRING of "E_ADD" */
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See help errsym for information on E_STRING errsym codes.
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For a list of the E_STRING associated with calc computation error
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codes, see help errorcodes.
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With errno() no argument:
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errno() returns the current value of "global calc_errno
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value". Unlike error() calling errno() does NOT increment
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the global calc error count (see help errcount).
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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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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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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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E_STRING is string that must match the regular expression: ^E_[A-Z0-9_]+$
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LINK LIBRARY
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int calc_errno; /* global calc_errno value */
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int set_errno(int e);
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CONST struct errtbl error_table[ECOUNT+2]; /* calc error codes, error symbols and error messages */
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bool is_e_digits(CONST char *errsym);
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bool is_valid_errnum(int errnum);
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bool is_errnum_in_error_table(int errnum);
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bool is_e_1string(CONST char *errsym);
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bool is_e_2string(CONST char *errsym);
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struct errtbl *find_errsym_in_errtbl(CONST char *errsym, CONST struct errtbl *tbl);
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struct errtbl *find_errnum_in_errtbl(int errnum, CONST struct errtbl *tbl);
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CONST struct errtbl *lookup_errnum_in_error_table(int errnum);
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int errsym_2_errnum(CONST char *errsym);
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char *errnum_2_errsym(int errnum, bool *palloced);
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char *errnum_2_errmsg(int errnum, bool *palloced);
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char *errsym_2_errmsg(CONST char *errsym, bool *palloced);
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SEE ALSO
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errcount, errmax, errorcodes, errsym, iserror, newerror, stoponerror, strerror
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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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