有时还是很有必要的:
#include <unistd.h> #include <fcntl.h> int access(const char *pPath, int mode); F_OK:文件是否存在 R_OK:读 W_OK:写 X_OK:执行 #define LOCK_FILE "quantum6.lock" if (access(LOCK_FILE, W_OK) != -1) { printf("%s can write.\n", LOCK_FILE); } else { printf("%s can not write.\n", LOCK_FILE); }