trip.c does not compile

[aeosynth]

[james@arch ~]$ cc --version
cc (GCC) 4.5.1
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[james@arch tmp]$ cc trip.c
trip.c: In function ‘init_lfsr113’:
trip.c:55:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
trip.c:55:3: note: use option -std=c99 or -std=gnu99 to compile your code
trip.c: In function ‘main’:
trip.c:98:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
trip.c:105:11: error: redefinition of ‘i’
trip.c:98:11: note: previous definition of ‘i’ was here
trip.c:105:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
trip.c: In function ‘trip_search’:
trip.c:148:5: error: ‘for’ loop initial declarations are only allowed in C99 mode

[james@arch tmp]$ cc trip.c -std=c99
trip.c: In function ‘init_lfsr113’:
trip.c:50:1: warning: implicit declaration of function ‘seed48’
trip.c:50:27: warning: initialization makes pointer from integer without a cast
trip.c:51:3: warning: implicit declaration of function ‘nrand48’
trip.c: In function ‘main’:
trip.c:76:3: warning: implicit declaration of function ‘getopt’
trip.c:82:17: error: ‘optarg’ undeclared (first use in this function)
trip.c:82:17: note: each undeclared identifier is reported only once for each function it appears in
trip.c:92:6: error: ‘optind’ undeclared (first use in this function)
trip.c:97:3: warning: implicit declaration of function ‘srand48’
trip.c:100:5: warning: implicit declaration of function ‘lrand48’

[james@arch tmp]$ cc trip.c -std=gnu99
/tmp/ccBidljP.o: In function `main':
trip.c:(.text+0x3f1): undefined reference to `pthread_create'
/tmp/ccBidljP.o: In function `trip_search':
trip.c:(.text+0x6a5): undefined reference to `pcre_compile'
trip.c:(.text+0x6e9): undefined reference to `pcre_study'
trip.c:(.text+0x730): undefined reference to `pcre_info'
trip.c:(.text+0x86d): undefined reference to `DES_fcrypt'
trip.c:(.text+0x8a4): undefined reference to `pcre_exec'
collect2: ld returned 1 exit status

trip-std.c has similar errors

edit: added gnu99, trip-std.c note

[lilyanatia]

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

[aeosynth]

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

[lilyanatia]

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).

[aeosynth]

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.

[lilyanatia]

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.

[aeosynth]

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.