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/*
* Fake Uname - version 0.1 - 2002/08/03 - Willy Tarreau <willy@w.ods.org>
*
* This uname implementation allows the user to display values according to
* environment variables, which is particularly helpful when compiling packages
* for other architectures or CPUs.
*
* Usage: uname [-amnrspv] (same as standard uname)
* -> machine (-m) will display the contents of UNAME_M if defined.
*
*/
#include <sys/utsname.h>
#include <stdlib.h>
#define F_MACH 1
#define F_NODE 2
#define F_REL 4
#define F_SYS 8
#define F_PROC 16
#define F_VER 32
#define F_ALL 63
char proc_name[] = "unknown";
char u_mach_env[] = "UNAME_M";
char usage_msg[] = "Usage: uname [-amnrspv]\n";
char opt[] = {
'a', F_ALL,
'm', F_MACH,
'n', F_NODE,
'r', F_REL,
's', F_SYS,
'p', F_PROC,
'v', F_VER,
0
};
char msg[1024];
struct utsname utsname;
/*
* copies at most <end-dst-2> chars from <src> to <dst>, adds a space, and
* always ends with a zero, unless <end-dst> is 0. <end> is always set to
* <msg+sizeof(msg)>, because in our case, the function is always used
* with this string. The pointer to the terminating zero is returned.
*/
static char *msgcpyspc(char *dst, const char *src) {
char *end = msg + sizeof(msg);
if (dst < end) {
end--;
while ((dst < end) && (*dst = *src)) {
src++; dst++;
}
if (dst < end)
*dst++ = ' ';
*dst = 0;
}
return dst;
}
static inline usage() {
write(2, usage_msg, sizeof(usage_msg)-1);
return 1;
}
main(int argc, char **argv) {
int i, options = 0;
char *next, *mach;
while (argc-- > 1) {
if (**++argv != '-')
return usage();
for (i = 0; ; i += 2) {
if (!opt[i])
return usage();
if (opt[i] == (*argv)[1]) {
options |= opt[i + 1];
break;
}
}
}
uname(&utsname);
mach = getenv(u_mach_env);
if (!options)
options = F_SYS; /* default behaviour is to return sysname */
next = msg;
if (options & F_SYS) next = msgcpyspc(next, utsname.sysname);
if (options & F_NODE) next = msgcpyspc(next, utsname.nodename);
if (options & F_REL) next = msgcpyspc(next, utsname.release);
if (options & F_VER) next = msgcpyspc(next, utsname.version);
if (options & F_MACH) {
if (mach) next = msgcpyspc(next, mach);
else next = msgcpyspc(next, utsname.machine);
}
if (options & F_PROC) next = msgcpyspc(next, proc_name);
if (next > msg) {
*(next - 1) = '\n'; /* changes last space for a newline */
write(1, msg, next - msg);
}
return 0;
}
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