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Diffstat (limited to 'glpk-5.0/src/misc/str2int.c')
-rw-r--r-- | glpk-5.0/src/misc/str2int.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/glpk-5.0/src/misc/str2int.c b/glpk-5.0/src/misc/str2int.c new file mode 100644 index 0000000..20325d5 --- /dev/null +++ b/glpk-5.0/src/misc/str2int.c @@ -0,0 +1,90 @@ +/* str2int.c (convert string to int) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* Copyright (C) 2000 Free Software Foundation, Inc. +* Written by Andrew Makhorin <mao@gnu.org>. +* +* GLPK is free software: you can redistribute it and/or modify it +* under the terms of the GNU General Public License as published by +* the Free Software Foundation, either version 3 of the License, or +* (at your option) any later version. +* +* GLPK is distributed in the hope that it will be useful, but WITHOUT +* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public +* License for more details. +* +* You should have received a copy of the GNU General Public License +* along with GLPK. If not, see <http://www.gnu.org/licenses/>. +***********************************************************************/ + +#include "misc.h" +#include "stdc.h" + +/*********************************************************************** +* NAME +* +* str2int - convert character string to value of int type +* +* SYNOPSIS +* +* #include "misc.h" +* int str2int(const char *str, int *val); +* +* DESCRIPTION +* +* The routine str2int converts the character string str to a value of +* integer type and stores the value into location, which the parameter +* val points to (in the case of error content of this location is not +* changed). +* +* RETURNS +* +* The routine returns one of the following error codes: +* +* 0 - no error; +* 1 - value out of range; +* 2 - character string is syntactically incorrect. */ + +int str2int(const char *str, int *val_) +{ int d, k, s, val = 0; + /* scan optional sign */ + if (str[0] == '+') + s = +1, k = 1; + else if (str[0] == '-') + s = -1, k = 1; + else + s = +1, k = 0; + /* check for the first digit */ + if (!isdigit((unsigned char)str[k])) + return 2; + /* scan digits */ + while (isdigit((unsigned char)str[k])) + { d = str[k++] - '0'; + if (s > 0) + { if (val > INT_MAX / 10) + return 1; + val *= 10; + if (val > INT_MAX - d) + return 1; + val += d; + } + else /* s < 0 */ + { if (val < INT_MIN / 10) + return 1; + val *= 10; + if (val < INT_MIN + d) + return 1; + val -= d; + } + } + /* check for terminator */ + if (str[k] != '\0') + return 2; + /* conversion has been done */ + *val_ = val; + return 0; +} + +/* eof */ |