1STRTOL(3P)                 POSIX Programmer's Manual                STRTOL(3P)
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PROLOG

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.
10

NAME

12       strtol, strtoll - convert a string to a long integer
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SYNOPSIS

15       #include <stdlib.h>
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17       long strtol(const char  *restrict  str,  char  **restrict  endptr,  int
18       base);
19       long long strtoll(const char *restrict str, char **restrict endptr,
20              int base)
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22

DESCRIPTION

24       These functions shall convert the initial portion of the string pointed
25       to by str to a type long and long  long  representation,  respectively.
26       First, they decompose the input string into three parts:
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28        1. An  initial, possibly empty, sequence of white-space characters (as
29           specified by isspace())
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31        2. A subject sequence interpreted as an integer  represented  in  some
32           radix determined by the value of base
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34        3. A  final  string  of one or more unrecognized characters, including
35           the terminating null byte of the input string.
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37       Then they shall attempt to convert the subject sequence to an  integer,
38       and return the result.
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40       If the value of base is 0, the expected form of the subject sequence is
41       that of a decimal constant, octal constant,  or  hexadecimal  constant,
42       any  of  which may be preceded by a '+' or '-' sign. A decimal constant
43       begins with a non-zero digit, and consists of  a  sequence  of  decimal
44       digits.  An  octal  constant consists of the prefix '0' optionally fol‐
45       lowed by a sequence of the digits '0' to '7' only.  A hexadecimal  con‐
46       stant  consists  of  the  prefix 0x or 0X followed by a sequence of the
47       decimal digits and letters 'a' (or 'A' ) to 'f' (or 'F' )  with  values
48       10 to 15 respectively.
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50       If the value of base is between 2 and 36, the expected form of the sub‐
51       ject sequence is a sequence of letters and digits representing an inte‐
52       ger  with  the radix specified by base, optionally preceded by a '+' or
53       '-' sign. The letters from 'a' (or 'A' ) to 'z' (or 'Z' ) inclusive are
54       ascribed  the  values  10 to 35; only letters whose ascribed values are
55       less than that of base are permitted. If the value of base is  16,  the
56       characters  0x or 0X may optionally precede the sequence of letters and
57       digits, following the sign if present.
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59       The subject sequence is defined as the longest initial  subsequence  of
60       the  input  string,  starting  with the first non-white-space character
61       that is of the expected form. The subject  sequence  shall  contain  no
62       characters  if the input string is empty or consists entirely of white-
63       space characters, or if the first non-white-space  character  is  other
64       than a sign or a permissible letter or digit.
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66       If  the subject sequence has the expected form and the value of base is
67       0, the sequence of characters starting with the first  digit  shall  be
68       interpreted  as  an  integer  constant. If the subject sequence has the
69       expected form and the value of base is between 2 and 36,  it  shall  be
70       used  as the base for conversion, ascribing to each letter its value as
71       given above. If the subject sequence begins  with  a  minus  sign,  the
72       value  resulting from the conversion shall be negated. A pointer to the
73       final string shall be stored in the object pointed to by  endptr,  pro‐
74       vided that endptr is not a null pointer.
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76       In  other  than  the C  or POSIX  locales, other implementation-defined
77       subject sequences may be accepted.
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79       If the subject sequence is empty or does not have the expected form, no
80       conversion  is  performed;  the  value  of  str is stored in the object
81       pointed to by endptr, provided that endptr is not a null pointer.
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83       The strtol() function shall not change the setting of errno if success‐
84       ful.
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86       Since  0,  {LONG_MIN} or {LLONG_MIN}, and {LONG_MAX} or {LLONG_MAX} are
87       returned on error and are also valid returns on success, an application
88       wishing  to check for error situations should set errno to 0, then call
89       strtol() or strtoll(), then check errno.
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RETURN VALUE

92       Upon successful completion, these functions shall return the  converted
93       value, if any. If no conversion could be performed, 0 shall be returned
94       and errno may be set to [EINVAL].
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96       If the correct value is outside  the  range  of  representable  values,
97       {LONG_MIN},  {LONG_MAX},  {LLONG_MIN}, or {LLONG_MAX} shall be returned
98       (according to the sign of the value), and errno set to [ERANGE].
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ERRORS

101       These functions shall fail if:
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103       ERANGE The value to be returned is not representable.
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105
106       These functions may fail if:
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108       EINVAL The value of base is not supported.
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111       The following sections are informative.
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EXAMPLES

114       None.
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APPLICATION USAGE

117       None.
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RATIONALE

120       None.
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FUTURE DIRECTIONS

123       None.
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SEE ALSO

126       isalpha(),  scanf(),  strtod(),  the   Base   Definitions   volume   of
127       IEEE Std 1003.1-2001, <stdlib.h>
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130       Portions  of  this text are reprinted and reproduced in electronic form
131       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
132       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
133       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
134       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
135       event of any discrepancy between this version and the original IEEE and
136       The  Open Group Standard, the original IEEE and The Open Group Standard
137       is the referee document. The original Standard can be  obtained  online
138       at http://www.opengroup.org/unix/online.html .
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142IEEE/The Open Group                  2003                           STRTOL(3P)
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