smehta@SumitMehta-EeePC:~$ gcc signals.c
signals.c:1:76: error: stdio.h: No such file or directory
signals.c:2:76: error: unistd.h: No such file or directory
signals.c:3:76: error: signal.h: No such file or directory
signals.c: In function ‘catch_read’:
signals.c:11: error: ‘sigset_t’ undeclared (first use in this function)
signals.c:11: error: (Each undeclared identifier is reported only once
signals.c:11: error: for each function it appears in.)
signals.c:11: error: expected ‘;’ before ‘mask_set’
signals.c:12: error: expected ‘;’ before ‘old_set’
signals.c:15: error: ‘SIGSEGV’ undeclared (first use in this function)
signals.c:17: error: ‘mask_set’ undeclared (first use in this function)
signals.c:18: error: ‘SIG_SETMASK’ undeclared (first use in this function)
signals.c:18: error: ‘old_set’ undeclared (first use in this function)
signals.c: In function ‘catch_write’:
signals.c:28: error: ‘sigset_t’ undeclared (first use in this function)
signals.c:28: error: expected ‘;’ before ‘mask_set’
signals.c:29: error: expected ‘;’ before ‘old_set’
signals.c:32: error: ‘SIGSEGV’ undeclared (first use in this function)
signals.c:34: error: ‘mask_set’ undeclared (first use in this function)
signals.c:35: error: ‘SIG_SETMASK’ undeclared (first use in this function)
signals.c:35: error: ‘old_set’ undeclared (first use in this function)
signals.c: In function ‘main’:
signals.c:48: error: ‘SIGSEGV’ undeclared (first use in this function)
signals.c:49: error: redefinition of ‘i’
signals.c:45: error: previous definition of ‘i’ was here
signals.c:49: error: ‘for’ loop initial declaration used outside C99 mode
signals.c:51: error: invalid lvalue in unary ‘&’
signals.c:53: warning: incompatible implicit declaration of built-in function ‘printf’