This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Since  the  value  of  *endptr  is unspecified if the value of base is not supported, applications should
       either ensure that base has a supported value (0 or between 2 and 36) before the call, or  check  for  an
       [EINVAL] error before examining *endptr.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                     STRTOIMAX(3POSIX)

       The  functionality  described  on  this  reference  page is aligned with the ISO C standard. Any conflict
       between the requirements described  here  and  the  ISO C  standard  is  unintentional.  This  volume  of
       POSIX.1‐2017 defers to the ISO C standard.

       These  functions  shall  be  equivalent  to the strtol(), strtoll(), strtoul(), and strtoull() functions,
       except  that  the  initial  portion  of  the  string  shall  be  converted  to  intmax_t  and   uintmax_t
       representation, respectively.

       These functions shall fail if:

       EINVAL The value of base is not supported.

       ERANGE The value to be returned is not representable.

       These functions may fail if:

       EINVAL No conversion could be performed.

       Thefollowingsectionsareinformative.

       None.

       None.

       strtoimax, strtoumax — convert string to integer type

       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.

       None.

       These functions shall return the converted value, if any.

       If no conversion could be performed, zero shall be returned and errno may be set to [EINVAL].

       If the value of base is not supported, 0 shall be returned and errno shall be set to [EINVAL].

       If  the  correct  value  is  outside  the  range  of representable values, {INTMAX_MAX}, {INTMAX_MIN}, or
       {UINTMAX_MAX} shall be returned (according to the return type and sign of the value, if any),  and  errno
       shall be set to [ERANGE].

strtol(), strtoul()

       The Base Definitions volume of POSIX.1‐2017, <inttypes.h>

       #include <inttypes.h>

       intmax_t strtoimax(const char *restrict nptr, char **restrict endptr,
           int base);
       uintmax_t strtoumax(const char *restrict nptr, char **restrict endptr,
           int base);