Message |
Code |
Details |
Operation not permitted |
EPERM |
Indicates that the requested operation cannot be done for some reason,
usually caused by misconfigurations or lack of system support/resources.
Note: Some platforms (e.g. Solaris) actually translate the
EACCES code to this message, which is confusing.
|
Permission denied |
EACCES |
Means that the request operation is not allowed due to access controls:
the logged-in user does not have sufficient filesystem permissions
to open/read/write/delete a file/directory, the logged-in user (or
client) is barred from access by configuration, etc.
|
Invalid argument |
EINVAL |
This generic message indicates that the supplied parameters are
considered invalid; the reasons behind this are myriad, depending on
the requested operation.
|
No such file or directory |
ENOENT |
The requested resource does not exist; can apply to files,
directories, and other non-filesystem resources.
|
Is a directory |
EISDIR |
The requested operation expects to operate on a file, but the
requested resource was a directory, not a file.
|
Bad file descriptor |
EBADF |
Read/write/close/delete operation on a file was requested on a
file descriptor which was not already opened.
|
Address already in use |
EADDRINUSE |
Process is attempting to listen on a network address/port which is
already bound; usually some other process on the system is listening
on that address (e.g. inetd /xinetd ).
|
Broken pipe |
EPIPE |
Process tried to send something to a connected TCP peer, and found
out that the connection had already been closed; can happen when
a firewall/router/NAT between TCP peers silently closes the connection
without informing one or both peers.
|
Connection reset by peer |
ECONNRESET |
Remote TCP peer sent the RST TCP flag, indicating that
the connection should be reset; this almost always indicates an
issue with the connected client (or some firewall/router/NAT device
between the client and the server).
|
Connection refused |
ECONNREFUSED |
The remote peer refused to accept the TCP connection; could be
firewalls/routers/NATs in the way, other network ACLs that deny the
connection, etc.
|
Too many open files |
EMFILE |
Per-process limit of number of open files (including sockets)
has been reached.
|
Too many open files in system |
ENFILE |
System-wide limit of number of open files (including sockets)
has been reached.
|