#include<stdio.h> int main(int argc, char* argv[ ]) { int i; char **ptr; extern char **environ; for( ptr = environ; *ptr...

#define _POSIX_SOURCE #define _POSIX_C_SOURCE 199309L #include<stdio.h> #include<unistd.h> int main() { #ifdef _POSIX_JOB_CONTROL printf("System supports job control\n"); #else printf("System does not...

#define _POSIX_SOURCE #define _POSIX_C_SOURCE 199309L #include<stdio.h> #include<unistd.h> int main() { int res; if((res = sysconf(_SC_OPEN_MAX)) == -1) perror("sysconf"); else printf("OPEN_MAX:%d\n",res);...

PROCEDURE: We make use of the following two functions in the process. look up() – it takes string as argument...