GNU/Linux |
RedHat 5.2(Apollo) |
|
![]() |
truncate(2) |
![]() |
truncate, ftruncate − truncate a file to a specified length
#include <unistd.h>
int
truncate(const char *path, size_t
length);
int ftruncate(int fd, size_t
length);
Truncate causes the file named by path or referenced by fd to be truncated to at most length bytes in size. If the file previously was larger than this size, the extra data is lost. With ftruncate, the file must be open for writing.
On success, zero is returned. On error, −1 is returned, and errno is set appropriately.
For truncate:
ENOTDIR |
A component of the path prefix is not a directory. | ||
EINVAL |
The pathname contains a character with the high-order bit set. |
ENAMETOOLONG
A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
ENOENT |
The named file does not exist. | ||
EACCES |
Search permission is denied for a component of the path prefix. | ||
EACCES |
The named file is not writable by the user. | ||
ELOOP |
Too many symbolic links were encountered in translating the pathname. | ||
EISDIR |
The named file is a directory. | ||
EROFS |
The named file resides on a read-only file system. | ||
ETXTBSY |
The file is a pure procedure (shared text) file that is being executed. | ||
EIO |
An I/O error occurred updating the inode. | ||
EFAULT |
Path points outside the process’s allocated address space. |
For Ftruncate:
EBADF |
The fd is not a valid descriptor. |
|||
EINVAL |
The fd references a socket, not a file. |
|||
EINVAL |
The fd is not open for writing. |
4.4BSD, SVr4 (these function calls first appeared in BSD 4.2). SVr4 documents additional truncate error conditions EINTR, EMFILE, EMULTIHP, ENAMETOOLONG, ENFILE, ENOLINK, ENOTDIR. SVr4 ftruncate documents additional EAGAIN and EINTR error conditions.
These calls should be generalized to allow ranges of bytes in a file to be discarded.
open(2)
![]() |
truncate(2) | ![]() |