Question

I am trying to compile some code on linux that I KNOW compiles on OSX, but I am getting some issues.

All of the files have headers named .h, and all of the files are in the same directory. I am compiling like this:

gcc *.c -std=c99 -lpthread

And while this code does compile on OSX, I get a bunch of weird linker errors on my Ubuntu install. Am I missing a few compiler options? It is a default Ubuntu-server install with the additional packages gcc and build-essential installed.

In file included from errorLogger.h:24:0,
                 from configParser.h:17,
                 from configParser.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
configParser.c: In function ‘parseConfigFile’:
configParser.c:114:5: warning: implicit declaration of function ‘getline’ [-Wimplicit-function-declaration]
In file included from errorLogger.h:24:0,
                 from global.h:18,
                 from connection.h:19,
                 from connection.c:10:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
connection.c: In function ‘createConnectionQueue’:
connection.c:189:28: warning: assignment makes integer from pointer without a cast [enabled by default]
In file included from errorLogger.h:24:0,
                 from database.h:16,
                 from database.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
In file included from errorLogger.h:24:0,
                 from errorLogger.c:10:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
errorLogger.c: In function ‘reportError’:
errorLogger.c:63:5: warning: implicit declaration of function ‘strerror_r’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘logMessage’:
errorLogger.c:87:5: warning: implicit declaration of function ‘localtime_r’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘processErrorQueue’:
errorLogger.c:131:17: warning: implicit declaration of function ‘open’ [-Wimplicit-function-declaration]
errorLogger.c:131:57: error: ‘O_APPEND’ undeclared (first use in this function)
errorLogger.c:131:57: note: each undeclared identifier is reported only once for each function it appears in
errorLogger.c:131:68: error: ‘O_CREAT’ undeclared (first use in this function)
errorLogger.c:131:78: error: ‘O_WRONLY’ undeclared (first use in this function)
errorLogger.c:131:88: error: ‘S_IWRITE’ undeclared (first use in this function)
errorLogger.c:131:99: error: ‘S_IREAD’ undeclared (first use in this function)
errorLogger.c:146:13: warning: implicit declaration of function ‘fsync’ [-Wimplicit-function-declaration]
errorLogger.c: In function ‘startErrorLogger’:
errorLogger.c:167:36: error: ‘O_APPEND’ undeclared (first use in this function)
errorLogger.c:167:47: error: ‘O_CREAT’ undeclared (first use in this function)
errorLogger.c:167:57: error: ‘O_WRONLY’ undeclared (first use in this function)
errorLogger.c:167:67: error: ‘S_IWRITE’ undeclared (first use in this function)
errorLogger.c:167:78: error: ‘S_IREAD’ undeclared (first use in this function)
errorLogger.c:214:57: error: ‘O_EXCL’ undeclared (first use in this function)
errorLogger.c:231:27: warning: assignment makes integer from pointer without a cast [enabled by default]
errorLogger.c: In function ‘closeErrorLogger’:
errorLogger.c:246:9: warning: implicit declaration of function ‘pthread_kill’ [-Wimplicit-function-declaration]
In file included from errorLogger.h:24:0,
                 from global.h:18,
                 from global.c:9:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
In file included from main.c:23:0:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
main.c: In function ‘main’:
main.c:53:5: warning: implicit declaration of function ‘blockSignals’ [-Wimplicit-function-declaration]
main.c:61:45: error: invalid application of ‘sizeof’ to incomplete type ‘struct addrinfo’ 
main.c:62:29: error: invalid application of ‘sizeof’ to incomplete type ‘struct addrinfo’ 
main.c:64:10: error: dereferencing pointer to incomplete type
main.c:65:10: error: dereferencing pointer to incomplete type
main.c:66:10: error: dereferencing pointer to incomplete type
main.c:66:23: error: ‘AI_PASSIVE’ undeclared (first use in this function)
main.c:66:23: note: each undeclared identifier is reported only once for each function it appears in
main.c:69:5: warning: implicit declaration of function ‘getaddrinfo’ [-Wimplicit-function-declaration]
main.c:73:9: warning: implicit declaration of function ‘gai_strerror’ [-Wimplicit-function-declaration]
main.c:73:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘int’ [-Wformat]
main.c:73:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 4 has type ‘int’ [-Wformat]
main.c:81:41: error: dereferencing pointer to incomplete type
main.c:83:30: error: dereferencing pointer to incomplete type
main.c:83:46: error: dereferencing pointer to incomplete type
main.c:83:64: error: dereferencing pointer to incomplete type
main.c:96:30: error: dereferencing pointer to incomplete type
main.c:96:44: error: dereferencing pointer to incomplete type
main.c:112:5: warning: implicit declaration of function ‘freeaddrinfo’ [-Wimplicit-function-declaration]
main.c:138:9: error: unknown type name ‘fd_set’
main.c:142:9: warning: implicit declaration of function ‘FD_ZERO’ [-Wimplicit-function-declaration]
main.c:143:9: warning: implicit declaration of function ‘FD_SET’ [-Wimplicit-function-declaration]
main.c:145:9: warning: implicit declaration of function ‘pselect’ [-Wimplicit-function-declaration]
In file included from signalHandling.c:10:0:
signalHandling.h:24:18: error: unknown type name ‘sigset_t’
signalHandling.c:12:18: error: unknown type name ‘sigset_t’
signalHandling.c: In function ‘setHandler’:
signalHandling.c:51:53: error: invalid application of ‘sizeof’ to incomplete type ‘struct sigaction’ 
signalHandling.c:52:36: error: invalid application of ‘sizeof’ to incomplete type ‘struct sigaction’ 
signalHandling.c:54:5: warning: implicit declaration of function ‘sigemptyset’ [-Wimplicit-function-declaration]
signalHandling.c:54:30: error: dereferencing pointer to incomplete type
signalHandling.c:60:9: warning: implicit declaration of function ‘sigaddset’ [-Wimplicit-function-declaration]
signalHandling.c:60:35: error: dereferencing pointer to incomplete type
signalHandling.c:67:17: error: dereferencing pointer to incomplete type
signalHandling.c:72:9: warning: implicit declaration of function ‘sigaction’ [-Wimplicit-function-declaration]

Answer 1

You are probably missing some #includes which are brought in implicitly on OS X, but not on Linux.

Judging from the error messages, you are probably missing includes for at least:

• <signal.h> (for sigset_t and others)
• <fcntl.h> (for O_*)
• <unistd.h> (for a bunch of stuff)
• <netdb.h> (for various network functions and constants)
• <stdio.h> (for getline)

You may also need to define some feature macros (e.g, _POSIX_C_SOURCE) to get certain system-dependent functions, including strerror_r and pselect.