Originální popis anglicky:
atoi - convert a string to an integer
Návod, kniha: POSIX Programmer's Manual
#include <stdlib.h>
int atoi(const char *
str);
The call
atoi(
str) shall be equivalent to:
(int) strtol(str, (char **)NULL, 10)
except that the handling of errors may differ. If the value cannot be
represented, the behavior is undefined.
The
atoi() function shall return the converted value if the value can be
represented.
No errors are defined.
The following sections are informative.
The following example checks for proper usage of the program. If there is an
argument and the decimal conversion of this argument (obtained using
atoi()) is greater than 0, then the program has a valid number of
minutes to wait for an event.
#include <stdlib.h>
#include <stdio.h>
...
int minutes_to_event;
...
if (argc < 2 || ((minutes_to_event = atoi (argv[1]))) <= 0) {
fprintf(stderr, "Usage: %s minutes\n", argv[0]); exit(1);
}
...
The
atoi() 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
atoi() is not
required to perform any error checking.
None.
None.
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 original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
