...f an exec (3). A C program can manipulate its environment using the functions getenv (3), putenv (3), setenv (3), and unsetenv (3). What follows is a list of environment variabl…...e() lrand48() mrand48() nftw() nl_langinfo() ptsname() putc_unlocked() putchar_unlocked() putenv() pututxline() rand() readdir() setenv() setgrent() setkey() setpwent() setutxen…