Ioctl get error code. h> int ioctl(int fd, unsigned long op, ); /* glibc, BSD */ int ioctl(int fd, int op, ); /* musl, other UNIX */ DESCRIPTION top The ioctl () system call manipulates the underlying device parameters of special files. The explain_ioctl function is used to obtain an explanation of an error returned by the ioctl (2) system call. . com However, it is also very easy to get ioctl command definitions wrong, and hard to fix them later without breaking existing applications, so this documentation tries to help developers get it right. I/O control codes are sent using IRPs. Dec 20, 2016 · Is the above code correct and a good programming practice? It does compile on my PC. Request-specific error codes are listed in the individual requests descriptions. 1. See full list on learn. Dec 14, 2021 · The IOCTL_STORAGE_ XXX control codes have identical values for function code, transfer method, and required access as the previous disk, tape, and CD-ROM codes. A few ioctl () operations use the return value as an output parameter and return a nonnegative value on success. Unix dd command variant, uses SG_IO ioctl to send SCSI commands to copy data. Generic Error Codes Note This list is not exaustive; ioctls may return other error codes. User-mode applications send IOCTLs to drivers by calling DeviceIoControl, which is described in Microsoft Windows SDK documentation. The least the message will contain is the value of strerror (errno), but usually it will do much better, and indicate the underlying cause in more detail. The storage class driver initiates some of these requests, but usually it is an application that does so. h (0p), netdb. RETURN VALUE top Usually, on success zero is returned. 0 | Entries: 760 | Apr 9, 2025 · I/O control codes (IOCTLs) are used for communication between user-mode applications and drivers, or for communication internally among drivers in a stack. i. Mar 13, 2022 · 为了避免ioctl调用错误，应该正确使用ioctl请求号，正确设置参数结构，处理ioctl函数返回值，以及避免使用ioctl函数。 如果能够遵循这些方法，就可以编写稳定和可靠的Linux程序，并避免由于ioctl调用错误而导致的不稳定性和安全性问题。 ioctl(2) System Calls Manual ioctl(2) NAME top ioctl - control device LIBRARY top Standard C library (libc, -lc) SYNOPSIS top #include <sys/ioctl. e does it populate err with the return value of ioctl and check if err is < 0 This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno. The source code for all the main utilities in table 1 is found in the src sub-directory. In particular, many operating Pages that refer to this page: errno. Since errors may have side effects such as a driver reset, applications should abort on unexpected errors, or otherwise assume that the device is in a bad state. On error, -1 is returned, and errno is set to indicate the error. h (0p), gawk (1), mv (1p), strace (1), accept (2), access (2), acct (2), add_key (2), adjtimex (2 Windows IOCTL referenceWindows IOCTL Reference | Extracted from DDK 7. microsoft. See the sg_dd retrieve descriptors, error history or data from device. The only difference is the device type. h (0p), signal. ghqm ajre bpuh pwqjyz zkrdg kyeqhl uwc kbidf dnuma ushb