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-rw-r--r--lib/sh/strtod.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/lib/sh/strtod.c b/lib/sh/strtod.c
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+++ b/lib/sh/strtod.c
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+/* strtod.c - convert string to double-precision floating-point value. */
+
+/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
+
+ This file is part of GNU Bash, the Bourne Again SHell.
+
+ Bash 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.
+
+ Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifndef HAVE_STRTOD
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include <chartypes.h>
+#include <math.h>
+
+#if HAVE_FLOAT_H
+# include <float.h>
+#else
+# define DBL_MAX 1.7976931348623159e+308
+# define DBL_MIN 2.2250738585072010e-308
+#endif
+
+#include <bashansi.h>
+
+#ifndef NULL
+# define NULL 0
+#endif
+
+#ifndef HUGE_VAL
+# define HUGE_VAL HUGE
+#endif
+
+/* Convert NPTR to a double. If ENDPTR is not NULL, a pointer to the
+ character after the last one used in the number is put in *ENDPTR. */
+double
+strtod (nptr, endptr)
+ const char *nptr;
+ char **endptr;
+{
+ register const char *s;
+ short sign;
+
+ /* The number so far. */
+ double num;
+
+ int got_dot; /* Found a decimal point. */
+ int got_digit; /* Seen any digits. */
+
+ /* The exponent of the number. */
+ long int exponent;
+
+ if (nptr == NULL)
+ {
+ errno = EINVAL;
+ goto noconv;
+ }
+
+ s = nptr;
+
+ /* Eat whitespace. */
+ while (ISSPACE ((unsigned char)*s))
+ ++s;
+
+ /* Get the sign. */
+ sign = *s == '-' ? -1 : 1;
+ if (*s == '-' || *s == '+')
+ ++s;
+
+ num = 0.0;
+ got_dot = 0;
+ got_digit = 0;
+ exponent = 0;
+ for (;; ++s)
+ {
+ if (DIGIT (*s))
+ {
+ got_digit = 1;
+
+ /* Make sure that multiplication by 10 will not overflow. */
+ if (num > DBL_MAX * 0.1)
+ /* The value of the digit doesn't matter, since we have already
+ gotten as many digits as can be represented in a `double'.
+ This doesn't necessarily mean the result will overflow.
+ The exponent may reduce it to within range.
+
+ We just need to record that there was another
+ digit so that we can multiply by 10 later. */
+ ++exponent;
+ else
+ num = (num * 10.0) + (*s - '0');
+
+ /* Keep track of the number of digits after the decimal point.
+ If we just divided by 10 here, we would lose precision. */
+ if (got_dot)
+ --exponent;
+ }
+ else if (!got_dot && *s == '.')
+ /* Record that we have found the decimal point. */
+ got_dot = 1;
+ else
+ /* Any other character terminates the number. */
+ break;
+ }
+
+ if (!got_digit)
+ goto noconv;
+
+ if (TOLOWER ((unsigned char)*s) == 'e')
+ {
+ /* Get the exponent specified after the `e' or `E'. */
+ int save = errno;
+ char *end;
+ long int exp;
+
+ errno = 0;
+ ++s;
+ exp = strtol (s, &end, 10);
+ if (errno == ERANGE)
+ {
+ /* The exponent overflowed a `long int'. It is probably a safe
+ assumption that an exponent that cannot be represented by
+ a `long int' exceeds the limits of a `double'. */
+ if (endptr != NULL)
+ *endptr = end;
+ if (exp < 0)
+ goto underflow;
+ else
+ goto overflow;
+ }
+ else if (end == s)
+ /* There was no exponent. Reset END to point to
+ the 'e' or 'E', so *ENDPTR will be set there. */
+ end = (char *) s - 1;
+ errno = save;
+ s = end;
+ exponent += exp;
+ }
+
+ if (endptr != NULL)
+ *endptr = (char *) s;
+
+ if (num == 0.0)
+ return 0.0;
+
+ /* Multiply NUM by 10 to the EXPONENT power,
+ checking for overflow and underflow. */
+
+ if (exponent < 0)
+ {
+ if (num < DBL_MIN * pow (10.0, (double) -exponent))
+ goto underflow;
+ }
+ else if (exponent > 0)
+ {
+ if (num > DBL_MAX * pow (10.0, (double) -exponent))
+ goto overflow;
+ }
+
+ num *= pow (10.0, (double) exponent);
+
+ return num * sign;
+
+overflow:
+ /* Return an overflow error. */
+ errno = ERANGE;
+ return HUGE_VAL * sign;
+
+underflow:
+ /* Return an underflow error. */
+ if (endptr != NULL)
+ *endptr = (char *) nptr;
+ errno = ERANGE;
+ return 0.0;
+
+noconv:
+ /* There was no number. */
+ if (endptr != NULL)
+ *endptr = (char *) nptr;
+ return 0.0;
+}
+
+#endif /* !HAVE_STRTOD */