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28 .\" @(#)truncate.2 8.1 (Berkeley) 6/4/93
29 .\" $FreeBSD: src/lib/libc/sys/truncate.2,v 1.7.2.6 2001/12/14 18:34:02 ru Exp $
30 .\" $DragonFly: src/lib/libc/sys/truncate.2,v 1.3 2006/02/17 19:35:06 swildner Exp $
38 .Nd truncate or extend a file to a specified length
44 .Fn truncate "const char *path" "off_t length"
46 .Fn ftruncate "int fd" "off_t length"
49 causes the file named by
53 to be truncated or extended to
55 bytes in size. If the file
56 was larger than this size, the extra data
58 If the file was smaller than this size,
59 it will be extended as if by writing bytes
63 the file must be open for writing.
71 A component of the path prefix is not a directory.
72 .It Bq Er ENAMETOOLONG
73 A component of a pathname exceeded 255 characters,
74 or an entire path name exceeded 1023 characters.
76 The named file does not exist.
78 Search permission is denied for a component of the path prefix.
80 The named file is not writable by the user.
82 Too many symbolic links were encountered in translating the pathname.
84 The named file is a directory.
86 The named file resides on a read-only file system.
88 The file is a pure procedure (shared text) file that is being executed.
90 An I/O error occurred updating the inode.
93 points outside the process's allocated address space.
102 is not a valid descriptor.
106 references a socket, not a file.
110 is not open for writing.
117 function call appeared in
120 These calls should be generalized to allow ranges
121 of bytes in a file to be discarded.
125 to extend a file is not portable.