1ATOL(3P) POSIX Programmer's Manual ATOL(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 atol, atoll — convert a string to a long integer
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16 #include <stdlib.h>
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18 long atol(const char *str);
19 long long atoll(const char *nptr);
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22 The functionality described on this reference page is aligned with the
23 ISO C standard. Any conflict between the requirements described here
24 and the ISO C standard is unintentional. This volume of POSIX.1‐2008
25 defers to the ISO C standard.
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27 The call atol(str) shall be equivalent to:
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29 strtol(str, (char **)NULL, 10)
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31 The call atoll(nptr) shall be equivalent to:
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33 strtoll(nptr, (char **)NULL, 10)
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35 except that the handling of errors may differ. If the value cannot be
36 represented, the behavior is undefined.
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39 These functions shall return the converted value if the value can be
40 represented.
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43 No errors are defined.
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45 The following sections are informative.
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48 None.
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51 The atol() function is subsumed by strtol() but is retained because it
52 is used extensively in existing code. If the number is not known to be
53 in range, strtol() should be used because atol() is not required to
54 perform any error checking.
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57 None.
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60 None.
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63 strtol()
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65 The Base Definitions volume of POSIX.1‐2008, <stdlib.h>
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68 Portions of this text are reprinted and reproduced in electronic form
69 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
70 -- Portable Operating System Interface (POSIX), The Open Group Base
71 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
72 cal and Electronics Engineers, Inc and The Open Group. (This is
73 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
74 event of any discrepancy between this version and the original IEEE and
75 The Open Group Standard, the original IEEE and The Open Group Standard
76 is the referee document. The original Standard can be obtained online
77 at http://www.unix.org/online.html .
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79 Any typographical or formatting errors that appear in this page are
80 most likely to have been introduced during the conversion of the source
81 files to man page format. To report such errors, see https://www.ker‐
82 nel.org/doc/man-pages/reporting_bugs.html .
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86IEEE/The Open Group 2013 ATOL(3P)