strtobool(9) centos man page | unix.com

STRTOBOOL(9)						     Basic C Library Functions						      STRTOBOOL(9)

NAME
       strtobool - convert common user inputs into boolean values

SYNOPSIS
       int strtobool(const char * s, bool * res);

ARGUMENTS
       s
	   input string

       res
	   result

DESCRIPTION
       This routine returns 0 iff the first character is one of 'Yy1Nn0'. Otherwise it will return -EINVAL. Value pointed to by res is updated
       upon finding a match.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							      STRTOBOOL(9)