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Diffstat (limited to 'man3/errno.3')
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diff --git a/man3/errno.3 b/man3/errno.3 deleted file mode 100644 index 335bb9c..0000000 --- a/man3/errno.3 +++ /dev/null @@ -1,655 +0,0 @@ -.\" Copyright (c) 1996 Andries Brouwer (aeb@cwi.nl) -.\" -.\" SPDX-License-Identifier: GPL-2.0-or-later -.\" -.\" 5 Oct 2002, Modified by Michael Kerrisk <mtk.manpages@gmail.com> -.\" Updated for POSIX.1 2001 -.\" 2004-12-17 Martin Schulze <joey@infodrom.org>, mtk -.\" Removed errno declaration prototype, added notes -.\" 2006-02-09 Kurt Wall, mtk -.\" Added non-POSIX errors -.\" -.TH errno 3 2023-10-31 "Linux man-pages 6.7" -.SH NAME -errno \- number of last error -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <errno.h> -.\".P -.\".BI "extern int " errno ; -.fi -.SH DESCRIPTION -The -.I <errno.h> -header file defines the integer variable -.IR errno , -which is set by system calls and some library functions in the event -of an error to indicate what went wrong. -.\" -.SS errno -The value in -.I errno -is significant only when the return value of -the call indicated an error -(i.e., \-1 from most system calls; -\-1 or NULL from most library functions); -a function that succeeds -.I is -allowed to change -.IR errno . -The value of -.I errno -is never set to zero by any system call or library function. -.P -For some system calls and library functions (e.g., -.BR getpriority (2)), -\-1 is a valid return on success. -In such cases, a successful return can be distinguished from an error -return by setting -.I errno -to zero before the call, and then, -if the call returns a status that indicates that an error -may have occurred, checking to see if -.I errno -has a nonzero value. -.P -.I errno -is defined by the ISO C standard to be a modifiable lvalue -of type -.IR int , -and must not be explicitly declared; -.I errno -may be a macro. -.I errno -is thread-local; setting it in one thread -does not affect its value in any other thread. -.\" -.SS Error numbers and names -Valid error numbers are all positive numbers. -The -.I <errno.h> -header file defines symbolic names for each -of the possible error numbers that may appear in -.IR errno . -.P -All the error names specified by POSIX.1 -must have distinct values, with the exception of -.B EAGAIN -and -.BR EWOULDBLOCK , -which may be the same. -On Linux, these two have the same value on all architectures. -.P -The error numbers that correspond to each symbolic name -vary across UNIX systems, -and even across different architectures on Linux. -Therefore, numeric values are not included as part of the list of -error names below. -The -.BR perror (3) -and -.BR strerror (3) -functions can be used to convert these names to -corresponding textual error messages. -.P -On any particular Linux system, -one can obtain a list of all symbolic error names and -the corresponding error numbers using the -.BR errno (1) -command (part of the -.I moreutils -package): -.P -.in +4n -.EX -$ \fBerrno \-l\fP -EPERM 1 Operation not permitted -ENOENT 2 No such file or directory -ESRCH 3 No such process -EINTR 4 Interrupted system call -EIO 5 Input/output error -\&... -.EE -.in -.P -The -.BR errno (1) -command can also be used to look up individual error numbers and names, -and to search for errors using strings from the error description, -as in the following examples: -.P -.in +4n -.EX -$ \fBerrno 2\fP -ENOENT 2 No such file or directory -$ \fBerrno ESRCH\fP -ESRCH 3 No such process -$ \fBerrno \-s permission\fP -EACCES 13 Permission denied -.EE -.in -.\".P -.\" POSIX.1 (2001 edition) lists the following symbolic error names. Of -.\" these, \fBEDOM\fP and \fBERANGE\fP are in the ISO C standard. ISO C -.\" Amendment 1 defines the additional error number \fBEILSEQ\fP for -.\" coding errors in multibyte or wide characters. -.\" -.SS List of error names -In the list of the symbolic error names below, -various names are marked as follows: -.TP -.I POSIX.1-2001 -The name is defined by POSIX.1-2001, -and is defined in later POSIX.1 versions, unless otherwise indicated. -.TP -.I POSIX.1-2008 -The name is defined in POSIX.1-2008, -but was not present in earlier POSIX.1 standards. -.TP -.I C99 -The name is defined by C99. -.P -Below is a list of the symbolic error names that are defined on Linux: -.TP 16 -.B E2BIG -Argument list too long (POSIX.1-2001). -.TP -.B EACCES -Permission denied (POSIX.1-2001). -.TP -.B EADDRINUSE -Address already in use (POSIX.1-2001). -.TP -.B EADDRNOTAVAIL -Address not available (POSIX.1-2001). -.\" EADV is only an error on HURD(?) -.TP -.B EAFNOSUPPORT -Address family not supported (POSIX.1-2001). -.TP -.B EAGAIN -Resource temporarily unavailable (may be the same value as -.BR EWOULDBLOCK ) -(POSIX.1-2001). -.TP -.B EALREADY -Connection already in progress (POSIX.1-2001). -.TP -.B EBADE -Invalid exchange. -.TP -.B EBADF -Bad file descriptor (POSIX.1-2001). -.TP -.B EBADFD -File descriptor in bad state. -.TP -.B EBADMSG -Bad message (POSIX.1-2001). -.TP -.B EBADR -Invalid request descriptor. -.TP -.B EBADRQC -Invalid request code. -.TP -.B EBADSLT -Invalid slot. -.\" EBFONT is defined but appears not to be used by kernel or glibc. -.TP -.B EBUSY -Device or resource busy (POSIX.1-2001). -.TP -.B ECANCELED -Operation canceled (POSIX.1-2001). -.TP -.B ECHILD -No child processes (POSIX.1-2001). -.TP -.B ECHRNG -Channel number out of range. -.TP -.B ECOMM -Communication error on send. -.TP -.B ECONNABORTED -Connection aborted (POSIX.1-2001). -.TP -.B ECONNREFUSED -Connection refused (POSIX.1-2001). -.TP -.B ECONNRESET -Connection reset (POSIX.1-2001). -.TP -.B EDEADLK -Resource deadlock avoided (POSIX.1-2001). -.TP -.B EDEADLOCK -On most architectures, a synonym for -.BR EDEADLK . -On some architectures (e.g., Linux MIPS, PowerPC, SPARC), -it is a separate error code "File locking deadlock error". -.TP -.B EDESTADDRREQ -Destination address required (POSIX.1-2001). -.TP -.B EDOM -Mathematics argument out of domain of function (POSIX.1, C99). -.\" EDOTDOT is defined but appears to be unused -.TP -.B EDQUOT -.\" POSIX just says "Reserved" -Disk quota exceeded (POSIX.1-2001). -.TP -.B EEXIST -File exists (POSIX.1-2001). -.TP -.B EFAULT -Bad address (POSIX.1-2001). -.TP -.B EFBIG -File too large (POSIX.1-2001). -.TP -.B EHOSTDOWN -Host is down. -.TP -.B EHOSTUNREACH -Host is unreachable (POSIX.1-2001). -.TP -.B EHWPOISON -Memory page has hardware error. -.TP -.B EIDRM -Identifier removed (POSIX.1-2001). -.TP -.B EILSEQ -Invalid or incomplete multibyte or wide character (POSIX.1, C99). -.IP -The text shown here is the glibc error description; -in POSIX.1, this error is described as "Illegal byte sequence". -.TP -.B EINPROGRESS -Operation in progress (POSIX.1-2001). -.TP -.B EINTR -Interrupted function call (POSIX.1-2001); see -.BR signal (7). -.TP -.B EINVAL -Invalid argument (POSIX.1-2001). -.TP -.B EIO -Input/output error (POSIX.1-2001). -.TP -.B EISCONN -Socket is connected (POSIX.1-2001). -.TP -.B EISDIR -Is a directory (POSIX.1-2001). -.TP -.B EISNAM -Is a named type file. -.TP -.B EKEYEXPIRED -Key has expired. -.TP -.B EKEYREJECTED -Key was rejected by service. -.TP -.B EKEYREVOKED -Key has been revoked. -.TP -.B EL2HLT -Level 2 halted. -.TP -.B EL2NSYNC -Level 2 not synchronized. -.TP -.B EL3HLT -Level 3 halted. -.TP -.B EL3RST -Level 3 reset. -.TP -.B ELIBACC -Cannot access a needed shared library. -.TP -.B ELIBBAD -Accessing a corrupted shared library. -.TP -.B ELIBMAX -Attempting to link in too many shared libraries. -.TP -.B ELIBSCN -\&.lib section in a.out corrupted -.TP -.B ELIBEXEC -Cannot exec a shared library directly. -.TP -.B ELNRNG -.\" ELNRNG appears to be used by a few drivers -Link number out of range. -.TP -.B ELOOP -Too many levels of symbolic links (POSIX.1-2001). -.TP -.B EMEDIUMTYPE -Wrong medium type. -.TP -.B EMFILE -Too many open files (POSIX.1-2001). -Commonly caused by exceeding the -.B RLIMIT_NOFILE -resource limit described in -.BR getrlimit (2). -Can also be caused by exceeding the limit specified in -.IR /proc/sys/fs/nr_open . -.TP -.B EMLINK -Too many links (POSIX.1-2001). -.TP -.B EMSGSIZE -Message too long (POSIX.1-2001). -.TP -.B EMULTIHOP -.\" POSIX says "Reserved" -Multihop attempted (POSIX.1-2001). -.TP -.B ENAMETOOLONG -Filename too long (POSIX.1-2001). -.\" ENAVAIL is defined, but appears not to be used -.TP -.B ENETDOWN -Network is down (POSIX.1-2001). -.TP -.B ENETRESET -Connection aborted by network (POSIX.1-2001). -.TP -.B ENETUNREACH -Network unreachable (POSIX.1-2001). -.TP -.B ENFILE -Too many open files in system (POSIX.1-2001). -On Linux, this is probably a result of encountering the -.I /proc/sys/fs/file\-max -limit (see -.BR proc (5)). -.TP -.B ENOANO -.\" ENOANO appears to be used by a few drivers -No anode. -.TP -.B ENOBUFS -No buffer space available (POSIX.1 (XSI STREAMS option)). -.\" ENOCSI is defined but appears to be unused. -.TP -.B ENODATA -The named attribute does not exist, -or the process has no access to this attribute; see -.BR xattr (7). -.IP -In POSIX.1-2001 (XSI STREAMS option), -this error was described as -"No message is available on the STREAM head read queue". -.TP -.B ENODEV -No such device (POSIX.1-2001). -.TP -.B ENOENT -No such file or directory (POSIX.1-2001). -.IP -Typically, this error results when a specified pathname does not exist, -or one of the components in the directory prefix of a pathname does not exist, -or the specified pathname is a dangling symbolic link. -.TP -.B ENOEXEC -Exec format error (POSIX.1-2001). -.TP -.B ENOKEY -Required key not available. -.TP -.B ENOLCK -No locks available (POSIX.1-2001). -.TP -.B ENOLINK -.\" POSIX says "Reserved" -Link has been severed (POSIX.1-2001). -.TP -.B ENOMEDIUM -No medium found. -.TP -.B ENOMEM -Not enough space/cannot allocate memory (POSIX.1-2001). -.TP -.B ENOMSG -No message of the desired type (POSIX.1-2001). -.TP -.B ENONET -Machine is not on the network. -.TP -.B ENOPKG -Package not installed. -.TP -.B ENOPROTOOPT -Protocol not available (POSIX.1-2001). -.TP -.B ENOSPC -No space left on device (POSIX.1-2001). -.TP -.B ENOSR -No STREAM resources (POSIX.1 (XSI STREAMS option)). -.TP -.B ENOSTR -Not a STREAM (POSIX.1 (XSI STREAMS option)). -.TP -.B ENOSYS -Function not implemented (POSIX.1-2001). -.TP -.B ENOTBLK -Block device required. -.TP -.B ENOTCONN -The socket is not connected (POSIX.1-2001). -.TP -.B ENOTDIR -Not a directory (POSIX.1-2001). -.TP -.B ENOTEMPTY -Directory not empty (POSIX.1-2001). -.\" ENOTNAM is defined but appears to be unused. -.TP -.B ENOTRECOVERABLE -State not recoverable (POSIX.1-2008). -.TP -.B ENOTSOCK -Not a socket (POSIX.1-2001). -.TP -.B ENOTSUP -Operation not supported (POSIX.1-2001). -.TP -.B ENOTTY -Inappropriate I/O control operation (POSIX.1-2001). -.TP -.B ENOTUNIQ -Name not unique on network. -.TP -.B ENXIO -No such device or address (POSIX.1-2001). -.TP -.B EOPNOTSUPP -Operation not supported on socket (POSIX.1-2001). -.IP -.RB ( ENOTSUP -and -.B EOPNOTSUPP -have the same value on Linux, but -according to POSIX.1 these error values should be distinct.) -.TP -.B EOVERFLOW -Value too large to be stored in data type (POSIX.1-2001). -.TP -.B EOWNERDEAD -.\" Used at least by the user-space side of rubost mutexes -Owner died (POSIX.1-2008). -.TP -.B EPERM -Operation not permitted (POSIX.1-2001). -.TP -.B EPFNOSUPPORT -Protocol family not supported. -.TP -.B EPIPE -Broken pipe (POSIX.1-2001). -.TP -.B EPROTO -Protocol error (POSIX.1-2001). -.TP -.B EPROTONOSUPPORT -Protocol not supported (POSIX.1-2001). -.TP -.B EPROTOTYPE -Protocol wrong type for socket (POSIX.1-2001). -.TP -.B ERANGE -Result too large (POSIX.1, C99). -.TP -.B EREMCHG -Remote address changed. -.TP -.B EREMOTE -Object is remote. -.TP -.B EREMOTEIO -Remote I/O error. -.TP -.B ERESTART -Interrupted system call should be restarted. -.TP -.B ERFKILL -.\" ERFKILL appears to be used by various drivers -Operation not possible due to RF-kill. -.TP -.B EROFS -Read-only filesystem (POSIX.1-2001). -.TP -.B ESHUTDOWN -Cannot send after transport endpoint shutdown. -.TP -.B ESPIPE -Invalid seek (POSIX.1-2001). -.TP -.B ESOCKTNOSUPPORT -Socket type not supported. -.TP -.B ESRCH -No such process (POSIX.1-2001). -.\" ESRMNT is defined but appears not to be used -.TP -.B ESTALE -Stale file handle (POSIX.1-2001). -.IP -This error can occur for NFS and for other filesystems. -.TP -.B ESTRPIPE -Streams pipe error. -.TP -.B ETIME -Timer expired -(POSIX.1 (XSI STREAMS option)). -.IP -(POSIX.1 says "STREAM -.BR ioctl (2) -timeout".) -.TP -.B ETIMEDOUT -Connection timed out (POSIX.1-2001). -.TP -.B ETOOMANYREFS -.\" ETOOMANYREFS seems to be used in net/unix/af_unix.c -Too many references: cannot splice. -.TP -.B ETXTBSY -Text file busy (POSIX.1-2001). -.TP -.B EUCLEAN -Structure needs cleaning. -.TP -.B EUNATCH -Protocol driver not attached. -.TP -.B EUSERS -Too many users. -.TP -.B EWOULDBLOCK -Operation would block (may be same value as -.BR EAGAIN ) -(POSIX.1-2001). -.TP -.B EXDEV -Invalid cross-device link (POSIX.1-2001). -.TP -.B EXFULL -Exchange full. -.SH NOTES -A common mistake is to do -.P -.in +4n -.EX -if (somecall() == \-1) { - printf("somecall() failed\en"); - if (errno == ...) { ... } -} -.EE -.in -.P -where -.I errno -no longer needs to have the value it had upon return from -.IR somecall () -(i.e., it may have been changed by the -.BR printf (3)). -If the value of -.I errno -should be preserved across a library call, it must be saved: -.P -.in +4n -.EX -if (somecall() == \-1) { - int errsv = errno; - printf("somecall() failed\en"); - if (errsv == ...) { ... } -} -.EE -.in -.P -Note that the POSIX threads APIs do -.I not -set -.I errno -on error. -Instead, on failure they return an error number as the function result. -These error numbers have the same meanings as the error numbers returned in -.I errno -by other APIs. -.P -On some ancient systems, -.I <errno.h> -was not present or did not declare -.IR errno , -so that it was necessary to declare -.I errno -manually -(i.e., -.IR "extern int errno" ). -.BR "Do not do this" . -It long ago ceased to be necessary, -and it will cause problems with modern versions of the C library. -.SH SEE ALSO -.BR errno (1), \" In the moreutils package -.BR err (3), -.BR error (3), -.BR perror (3), -.BR strerror (3) |