1 files changed, 46 insertions, 0 deletions
diff --git a/src/pdclib/functions/_PDCLIB/_PDCLIB_atomax.c b/src/pdclib/functions/_PDCLIB/_PDCLIB_atomax.c
new file mode 100644
index 0000000..eaf7ced
--- /dev/null
+++ b/src/pdclib/functions/_PDCLIB/_PDCLIB_atomax.c
@@ -0,0 +1,46 @@
+/* _PDCLIB_atomax( const char * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <string.h>
+#include <ctype.h>
+
+#ifndef REGTEST
+
+_PDCLIB_intmax_t _PDCLIB_atomax( const char * s )
+{
+    _PDCLIB_intmax_t rc = 0;
+    char sign = '+';
+    const char * x;
+    /* TODO: In other than "C" locale, additional patterns may be defined     */
+    while ( isspace( *s ) ) ++s;
+    if ( *s == '+' ) ++s;
+    else if ( *s == '-' ) sign = *(s++);
+    /* TODO: Earlier version was missing tolower() but was not caught by tests */
+    while ( ( x = memchr( _PDCLIB_digits, tolower(*(s++)), 10 ) ) != NULL )
+    {
+        rc = rc * 10 + ( x - _PDCLIB_digits );
+    }
+    return ( sign == '+' ) ? rc : -rc;
+}
+
+#endif
+
+#ifdef TEST
+
+#include "_PDCLIB_test.h"
+
+int main( void )
+{
+#ifndef REGTEST
+    /* basic functionality */
+    TESTCASE( _PDCLIB_atomax( "123" ) == 123 );
+    /* testing skipping of leading whitespace and trailing garbage */
+    TESTCASE( _PDCLIB_atomax( " \n\v\t\f123xyz" ) == 123 );
+#endif
+    return TEST_RESULTS;
+}
+
+#endif