TRUNCATE(3C-SVR4) RISC/os Reference Manual TRUNCATE(3C-SVR4)
NAME
truncate, ftruncate - set a file to a specified length
SYNOPSIS
#include <unistd.h>
int truncate (const char *path, offt length);
int ftruncate (int fildes, offt length);
DESCRIPTION
The file whose name is given by path or referenced by the
descriptor fildes has its size set to length bytes.
If the file was previously longer than length, bytes past
length will no longer be accessible. If it was shorter,
bytes from the EOF before the call to the EOF after the call
will be read in as zeros. The effective user ID of the pro-
cess must have write permission for the file, and for ftrun-
cate the file must be open for writing.
truncate fails if one or more of the following are true:
EACCES Search permission is denied on a component
of the path prefix.
EACCES Write permission is denied for the file
referred to by path.
EFAULT path points outside the process's allo-
cated address space.
EINTR A signal was caught during execution of
the truncate routine.
EINVAL path is not an ordinary file.
EIO An I/O error occurred while reading from
or writing to the file system.
EISDIR The file referred to by path is a direc-
tory.
ELOOP Too many symbolic links were encountered
in translating path.
EMFILE The maximum number of file descriptors
available to the process has been reached.
EMULTIHOP Components of path require hopping to mul-
tiple remote machines and file system type
does not allow it.
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TRUNCATE(3C-SVR4) RISC/os Reference Manual TRUNCATE(3C-SVR4)
ENAMETOOLONG The length of a path component exceeds
{NAME_MAX} characters, or the length of
path exceeds {PATH_MAX} characters.
ENFILE Could not allocate any more space for the
system file table.
ENOENT Either a component of the path prefix or
the file referred to by path does not
exist.
ENOLINK path points to a remote machine and the
link to that machine is no longer active.
ENOTDIR A component of the path prefix of path is
not a directory.
EROFS The file referred to by path resides on a
read-only file system.
ETXTBSY The file referred to by path is a pure
procedure (shared text) file that is being
executed.
ftruncate fails if one or more of the following are true:
EAGAIN The file exists, mandatory file/record
locking is set, and there are outstanding
record locks on the file [see chmod(2)].
EBADF fildes is not a file descriptor open for
writing.
EINTR A signal was caught during execution of
the ftruncate routine.
EIO An I/O error occurred while reading from
or writing to the file system.
ENOLINK fildes points to a remote machine and the
link to that machine is no longer active.
EINVAL fildes does not correspond to an ordinary
file.
SEE ALSO
fcntl(2), open(2)
DIAGNOSTICS
Upon successful completion, a value of 0 is returned. Oth-
erwise, a value of -1 is returned and errno is set to indi-
cate the error.
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