trip.c does not compile about trip HOT 6 CLOSED

learn to use your compiler.
-std=c99 -lpthread -lpcre -lcrypto

or, since your libc is apparently broken unless you use -std=gnu99,
-std=gnu99 -lpthread -lpcre -lcrypto

from trip.

I'm not a c hacker, so forgive me. This would have been easier if you had a readme. Could I get the right options to compile trip-std.c by any chance?

[james@arch trip]$ cc --std=gnu99 trip-std.c
trip-std.c: In function ‘trip_search’:
trip-std.c:124:5: warning: implicit declaration of function ‘crypt’
trip-std.c:124:5: warning: passing argument 2 of ‘memcpy’ makes pointer from integer without a cast
/usr/include/string.h:44:14: note: expected ‘const void * restrict’ but argument is of type ‘int’
/tmp/ccBr4xk0.o: In function `main':
trip-std.c:(.text+0x3c8): undefined reference to `pthread_create'
/tmp/ccBr4xk0.o: In function `trip_search':
trip-std.c:(.text+0x771): undefined reference to `crypt'
collect2: ld returned 1 exit status

from trip.

if your system doesn't have crypt, trip-std.c won't work for you.
if you can fix that, you'll need to link it against libpthread (-lpthread).

from trip.

I can get it to compile with -std=gnu99 -lpthread -lcrypt, but it just segfaults.

[james@arch trip]$ cc trip-std.c -o trip-std -std=gnu99 -lpthread -lcrypt 
trip-std.c: In function ‘trip_search’:
trip-std.c:124:5: warning: implicit declaration of function ‘crypt’
trip-std.c:124:5: warning: passing argument 2 of ‘memcpy’ makes pointer from integer without a cast
/usr/include/string.h:44:14: note: expected ‘const void * restrict’ but argument is of type ‘int’
[james@arch trip]$ ./trip-std wat
Segmentation fault

I'm on Arch Linux btw.

from trip.

those warnings are because crypt isn't declared in unistd.h like it should be.
"implicit declaration" means that it's assuming it's int crypt(int), when it should be char *crypt(const char *, const char *). that's probably why you're getting a segfault.
you could try adding a declaration for crypt, but the right way to fix it would be to figure out why your unistd.h doesn't declare crypt.

from trip.

I figured it out - the declaration in unistd.h is guarded by #ifdef __USE_XOPEN; adding #define __USE_XOPEN to trip-std.c makes it work.

from trip.