add some const correctness, NULL

[fstd]

In order to deal with a ton of compiler warnings, here's some const-correctness added.
While at it, replace a (char *)0 with NULL. Personally I'd use an initialization, but you don't seem to like initializations so whatever :).

The warnings this addresses are:

nweb23.c:27:3:

warning: initialization discards ‘const’ qualifier from pointer target type
{"gif", "image/gif" },
^
nweb23.c:27:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:28:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"jpg", "image/jpg" },
^
nweb23.c:28:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:29:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"jpeg","image/jpeg"},
^
nweb23.c:29:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:30:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"png", "image/png" },
^
nweb23.c:30:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:31:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"ico", "image/ico" },
^
nweb23.c:31:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:32:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"zip", "image/zip" },
^
nweb23.c:32:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:33:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"gz", "image/gz" },
^
nweb23.c:33:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:34:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"tar", "image/tar" },
^
nweb23.c:34:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:35:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"htm", "text/html" },
^
nweb23.c:35:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c:36:3: warning: initialization discards ‘const’ qualifier from pointer target type
{"html","text/html" },
^
nweb23.c:36:3: warning: initialization discards ‘const’ qualifier from pointer target type
nweb23.c: In function ‘web’:
nweb23.c:76:22: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(FORBIDDEN,"failed to read browser request","",fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:76:55: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(FORBIDDEN,"failed to read browser request","",fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:84:14: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(LOG,"request",buffer,hit);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:86:22: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(FORBIDDEN,"Only simple GET operation supported",buffer,fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:96:24: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(FORBIDDEN,"Parent directory (..) path names not supported",buffer,fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:111:34: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
if(fstr == 0) logger(FORBIDDEN,"file extension type not supported",buffer,fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:114:22: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(NOTFOUND, "failed to open file",&buffer[5],fd);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:116:14: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(LOG,"SEND",&buffer[5],hit);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:120:14: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(LOG,"Header",buffer,hit);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c: In function ‘main’:
nweb23.c:174:14: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(LOG,"nweb starting",argv[1],getpid());
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:177:19: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR, "system call","socket",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:177:33: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR, "system call","socket",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:180:18: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"Invalid port number (try 1->60000)",argv[1],0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:185:18: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","bind",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:185:32: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","bind",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:187:18: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","listen",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:187:32: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","listen",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:191:20: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","accept",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:191:34: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","accept",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:193:20: warning: passing argument 2 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","fork",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^
nweb23.c:193:34: warning: passing argument 3 of ‘logger’ discards ‘const’ qualifier from pointer target type
logger(ERROR,"system call","fork",0);
^
nweb23.c:39:6: note: expected ‘char *’ but argument is of type ‘const char *’
void logger(int type, char *s1, char *s2, int socket_fd)
^

Cheers,
fstd