c program in linux to find the maximum length allowed for a host name

The following is a C program to find out the maximum length allowed for a host name in the system We can make use of the function sysconf and pass the argument _SC_HOST_NAME_MAX
We need the header file unistd.h to use sysconf.

#include<stdio.h> #include<unistd.h> #include<stdlib.h> main() { long temp; temp=sysconf(_SC_HOST_NAME_MAX); if(temp==-1) printf("Check the argument passed to sysconf"); printf("\nMaximum length for host name is : %d \n",temp); }

Save the program as get_max_hostname.c. Compile and execute the code.

$ cc get_max_hostname.c -o get_max_hostname $ ./get_max_hostname Maximum length for host name is : 64