STRTOL(3C) (C Programming Language Utilities) STRTOL(3C)
NAME
strtol, atol, atoi - convert string to integer
SYNOPSIS
long strtol (str, ptr, base)
char *str, **ptr;
int base;
long atol (str)
char *str;
int atoi (str)
char *str;
DESCRIPTION
strtol returns as a long integer the value represented by
the character string pointed to by str. The string is
scanned up to the first character inconsistent with the
base. Leading ``white-space'' characters [as defined by
isspace in ctype(3C)] are ignored.
If the value of ptr is not (char **)NULL, a pointer to the
character terminating the scan is returned in the location
pointed to by ptr. If no integer can be formed, that
location is set to str, and zero is returned.
If base is positive (and not greater than 36), it is used as
the base for conversion. After an optional leading sign,
leading zeros are ignored, and ``0x'' or ``0X'' is ignored
if base is 16.
If base is zero, the string itself determines the base
thusly: After an optional leading sign a leading zero
indicates octal conversion, and a leading ``0x'' or ``0X''
hexadecimal conversion. Otherwise, decimal conversion is
used.
Truncation from long to int can, of course, take place upon
assignment or by an explicit cast.
Page 1 May 1989
STRTOL(3C) (C Programming Language Utilities) STRTOL(3C)
Atol(str) is equivalent to strtol(str, (char **)NULL, 10).
Atoi(str) is equivalent to (int) strtol(str, (char **)NULL,
10).
SEE ALSO
ctype(3C), scanf(3S), strtod(3C).
CAVEAT
Overflow conditions are ignored.
Page 2 May 1989