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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /stdlib/strtol.c
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initial import
Diffstat (limited to 'stdlib/strtol.c')
-rw-r--r--stdlib/strtol.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/stdlib/strtol.c b/stdlib/strtol.c
new file mode 100644
index 0000000..888a94e
--- /dev/null
+++ b/stdlib/strtol.c
@@ -0,0 +1,189 @@
+/* Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc.
+
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <ctype.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <errno.h>
+
+/* Nonzero if we are defining `strtoul' or `strtouq', operating on unsigned
+ integers. */
+#ifndef UNSIGNED
+#define UNSIGNED 0
+#endif
+
+/* If QUAD is defined, we are defining `strtoq' or `strtouq',
+ operating on `long long int's. */
+#ifdef QUAD
+#if UNSIGNED
+#define strtoul strtouq
+#else
+#define strtol strtoq
+#endif
+#define LONG long long
+#undef LONG_MIN
+#define LONG_MIN LONG_LONG_MIN
+#undef LONG_MAX
+#define LONG_MAX LONG_LONG_MAX
+#undef ULONG_MAX
+#define ULONG_MAX ULONG_LONG_MAX
+#if __GNUC__ == 2 && __GNUC_MINOR__ < 7
+/* Work around gcc bug with using this constant. */
+static const unsigned long long int maxquad = ULONG_LONG_MAX;
+#undef ULONG_MAX
+#define ULONG_MAX maxquad
+#endif
+#else
+#define LONG long
+#endif
+
+/* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
+ If BASE is 0 the base is determined by the presence of a leading
+ zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
+ If BASE is < 2 or > 36, it is reset to 10.
+ If ENDPTR is not NULL, a pointer to the character after the last
+ one converted is stored in *ENDPTR. */
+#if UNSIGNED
+unsigned LONG int
+#define strtol strtoul
+#else
+LONG int
+#endif
+strtol (nptr, endptr, base)
+ const char *nptr;
+ char **endptr;
+ int base;
+{
+ int negative;
+ register unsigned LONG int cutoff;
+ register unsigned int cutlim;
+ register unsigned LONG int i;
+ register const char *s;
+ register unsigned char c;
+ const char *save;
+ int overflow;
+
+ if (base < 0 || base == 1 || base > 36)
+ base = 10;
+
+ s = nptr;
+
+ /* Skip white space. */
+ while (isspace (*s))
+ ++s;
+ if (*s == '\0')
+ goto noconv;
+
+ /* Check for a sign. */
+ if (*s == '-')
+ {
+ negative = 1;
+ ++s;
+ }
+ else if (*s == '+')
+ {
+ negative = 0;
+ ++s;
+ }
+ else
+ negative = 0;
+
+ if (base == 16 && s[0] == '0' && toupper (s[1]) == 'X')
+ s += 2;
+
+ /* If BASE is zero, figure it out ourselves. */
+ if (base == 0)
+ if (*s == '0')
+ {
+ if (toupper (s[1]) == 'X')
+ {
+ s += 2;
+ base = 16;
+ }
+ else
+ base = 8;
+ }
+ else
+ base = 10;
+
+ /* Save the pointer so we can check later if anything happened. */
+ save = s;
+
+ cutoff = ULONG_MAX / (unsigned LONG int) base;
+ cutlim = ULONG_MAX % (unsigned LONG int) base;
+
+ overflow = 0;
+ i = 0;
+ for (c = *s; c != '\0'; c = *++s)
+ {
+ if (isdigit (c))
+ c -= '0';
+ else if (isalpha (c))
+ c = toupper (c) - 'A' + 10;
+ else
+ break;
+ if (c >= base)
+ break;
+ /* Check for overflow. */
+ if (i > cutoff || (i == cutoff && c > cutlim))
+ overflow = 1;
+ else
+ {
+ i *= (unsigned LONG int) base;
+ i += c;
+ }
+ }
+
+ /* Check if anything actually happened. */
+ if (s == save)
+ goto noconv;
+
+ /* Store in ENDPTR the address of one character
+ past the last character we converted. */
+ if (endptr != NULL)
+ *endptr = (char *) s;
+
+#if !UNSIGNED
+ /* Check for a value that is within the range of
+ `unsigned LONG int', but outside the range of `LONG int'. */
+ if (i > (negative ?
+ -(unsigned LONG int) LONG_MIN : (unsigned LONG int) LONG_MAX))
+ overflow = 1;
+#endif
+
+ if (overflow)
+ {
+ errno = ERANGE;
+#if UNSIGNED
+ return ULONG_MAX;
+#else
+ return negative ? LONG_MIN : LONG_MAX;
+#endif
+ }
+
+ /* Return the result of the appropriate sign. */
+ return (negative ? -i : i);
+
+noconv:
+ /* There was no number to convert. */
+ if (endptr != NULL)
+ *endptr = (char *) nptr;
+ return 0L;
+}