ATOL(3P) POSIX Programmer's Manual ATOL(3P)
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of
this interface may differ (consult the corresponding Linux manual page for details of
Linux behavior), or the interface may not be implemented on Linux.
atol, atoll - convert a string to a long integer
long atol(const char *str);
long long atoll(const char *nptr);
The call atol(str) shall be equivalent to:
strtol(str, (char **)NULL, 10)
The call atoll(str) shall be equivalent to:
strtoll(nptr, (char **)NULL, 10)
except that the handling of errors may differ. If the value cannot be represented, the
behavior is undefined.
These functions shall return the converted value if the value can be represented.
No errors are defined.
The following sections are informative.
The atol() function is subsumed by strtol() but is retained because it is used extensively
in existing code. If the number is not known to be in range, strtol() should be used
because atol() is not required to perform any error checking.
strtol(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by
the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 ATOL(3P)