#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <fnmatch.h>
#include <err.h>
#include "archcommon.h"
bool variable_match(const char *iface, const char *variable, const char *pattern) {
// Map platform-independent variables to sysfs names
if(!strcasecmp(variable, "mac"))
variable = "address";
// Open the corresponding sysfs file
char *filename = NULL;
if(asprintf(&filename, "/sys/class/net/%s/%s", iface, variable) == -1 || !filename)
errx(1, "asprintf");
// Shortcut: * tests for file presence
if(!strcmp(pattern, "*"))
return access(filename, F_OK);
FILE *f = fopen(filename, "r");
if(!f)
return false;
// Match against any line
char buf[1024];
bool found = false;
while(fgets(buf, sizeof buf, f)) {
// strip newline
size_t len = strlen(buf);
if(len && buf[len - 1] == '\n')
buf[len - 1] = 0;
if(fnmatch(pattern, buf, FNM_EXTMATCH) == 0) {
found = true;
break;
}
}
fclose(f);
return found;
}