1RENAME(3P)                 POSIX Programmer's Manual                RENAME(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       rename - rename a file
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SYNOPSIS

15       #include <stdio.h>
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17       int rename(const char *old, const char *new);
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19

DESCRIPTION

21       The rename() function shall change the name of a file. The old argument
22       points  to  the  pathname  of  the file to be renamed. The new argument
23       points to the new pathname of the file.
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25       If either the old or new argument names a symbolic link, rename() shall
26       operate  on  the  symbolic  link itself, and shall not resolve the last
27       component of the argument. If the old argument  and  the  new  argument
28       resolve  to  the same existing file, rename() shall return successfully
29       and perform no other action.
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31       If the old argument points to the pathname of a  file  that  is  not  a
32       directory, the new argument shall not point to the pathname of a direc‐
33       tory. If the link named by the new argument exists, it shall be removed
34       and  old  renamed  to  new. In this case, a link named new shall remain
35       visible to other processes throughout the renaming operation and  refer
36       either  to  the  file  referred  to  by new or old before the operation
37       began. Write access permission is required for both the directory  con‐
38       taining old and the directory containing new.
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40       If  the  old  argument  points  to the pathname of a directory, the new
41       argument shall not point to the pathname of a file that is not a direc‐
42       tory.  If  the  directory named by the new argument exists, it shall be
43       removed and old renamed to new. In this case, a link  named  new  shall
44       exist  throughout  the renaming operation and shall refer either to the
45       directory referred to by new or old before the operation began. If  new
46       names an existing directory, it shall be required to be an empty direc‐
47       tory.
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49       If the old argument points to a pathname of a symbolic link,  the  sym‐
50       bolic  link  shall be renamed. If the new argument points to a pathname
51       of a symbolic link, the symbolic link shall be removed.
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53       The new pathname shall not contain a path prefix that names old.  Write
54       access  permission is required for the directory containing old and the
55       directory containing new.  If the old argument points to  the  pathname
56       of  a directory, write access permission may be required for the direc‐
57       tory named by old, and, if it exists, the directory named by new.
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59       If the link named by the new argument exists and the file's link  count
60       becomes  0  when  it  is  removed and no process has the file open, the
61       space occupied by the file shall be freed and the file shall no  longer
62       be  accessible.  If  one  or more processes have the file open when the
63       last link is  removed,  the  link  shall  be  removed  before  rename()
64       returns,  but the removal of the file contents shall be postponed until
65       all references to the file are closed.
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67       Upon successful completion, rename() shall mark for update the st_ctime
68       and st_mtime fields of the parent directory of each file.
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70       If  the  rename()  function  fails for any reason other than [EIO], any
71       file named by new shall be unaffected.
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RETURN VALUE

74       Upon successful completion, rename()  shall  return  0;  otherwise,  -1
75       shall  be  returned,    errno  shall be set to indicate the error,  and
76       neither the file named by old nor  the  file  named  by  new  shall  be
77       changed or created.
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ERRORS

80       The rename() function shall fail if:
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82       EACCES A  component  of either path prefix denies search permission; or
83              one of the directories containing old or new denies  write  per‐
84              missions;  or,  write permission is required and is denied for a
85              directory pointed to by the old or new arguments.
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87       EBUSY  The directory named by old or new is currently  in  use  by  the
88              system or another process, and the implementation considers this
89              an error.
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91       EEXIST or ENOTEMPTY
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93              The link named by new is a directory that is not an empty direc‐
94              tory.
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96       EINVAL The new directory pathname contains a path prefix that names the
97              old directory.
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99       EIO    A physical I/O error has occurred.
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101       EISDIR The new argument points to a  directory  and  the  old  argument
102              points to a file that is not a directory.
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104       ELOOP  A loop exists in symbolic links encountered during resolution of
105              the path argument.
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107       EMLINK The file named by old is a directory, and the link count of  the
108              parent directory of new would exceed {LINK_MAX}.
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110       ENAMETOOLONG
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112              The  length  of  the old or new argument exceeds {PATH_MAX} or a
113              pathname component is longer than {NAME_MAX}.
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115       ENOENT The link named by old does not name an existing file, or  either
116              old or new points to an empty string.
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118       ENOSPC The directory that would contain new cannot be extended.
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120       ENOTDIR
121              A component of either path prefix is not a directory; or the old
122              argument names a directory and new argument names  a  non-direc‐
123              tory file.
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125       EPERM or EACCES
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127              The  S_ISVTX  flag  is  set on the directory containing the file
128              referred to by old and the caller is not the file owner, nor  is
129              the  caller the directory owner, nor does the caller have appro‐
130              priate privileges; or  new  refers  to  an  existing  file,  the
131              S_ISVTX  flag  is set on the directory containing this file, and
132              the caller is not the file owner, nor is the caller  the  direc‐
133              tory owner, nor does the caller have appropriate privileges.
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135       EROFS  The  requested  operation  requires  writing in a directory on a
136              read-only file system.
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138       EXDEV  The links named by new and old are on different file systems and
139              the implementation does not support links between file systems.
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141
142       The rename() function may fail if:
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144       EBUSY  The file named by the old or new arguments is a named STREAM.
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146       ELOOP  More  than  {SYMLOOP_MAX} symbolic links were encountered during
147              resolution of the path argument.
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149       ENAMETOOLONG
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151              As a result of encountering a symbolic link in resolution of the
152              path  argument,  the  length  of the substituted pathname string
153              exceeded {PATH_MAX}.
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155       ETXTBSY
156              The file to be renamed is a pure procedure  (shared  text)  file
157              that is being executed.
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159
160       The following sections are informative.
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EXAMPLES

163   Renaming a File
164       The  following  example shows how to rename a file named /home/cnd/mod1
165       to /home/cnd/mod2.
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167
168              #include <stdio.h>
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170
171              int status;
172              ...
173              status = rename("/home/cnd/mod1", "/home/cnd/mod2");
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APPLICATION USAGE

176       Some implementations mark for update  the  st_ctime  field  of  renamed
177       files  and  some  do  not.  Applications which make use of the st_ctime
178       field may behave differently with respect to renamed files unless  they
179       are designed to allow for either behavior.
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RATIONALE

182       This  rename() function is equivalent for regular files to that defined
183       by the ISO C standard. Its inclusion here expands  that  definition  to
184       include  actions  on  directories  and  specifies behavior when the new
185       parameter names a file that already exists. That specification requires
186       that the action of the function be atomic.
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188       One of the reasons for introducing this function was to have a means of
189       renaming directories while permitting implementations to  prohibit  the
190       use of link() and unlink() with directories, thus constraining links to
191       directories to those made by mkdir().
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193       The specification that if old  and  new  refer  to  the  same  file  is
194       intended to guarantee that:
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196
197              rename("x", "x");
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199       does not remove the file.
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201       Renaming dot or dot-dot is prohibited in order to prevent cyclical file
202       system paths.
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204       See also the descriptions of [ENOTEMPTY] and [ENAMETOOLONG] in  rmdir()
205       and [EBUSY] in unlink(). For a discussion of [EXDEV], see link() .
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FUTURE DIRECTIONS

208       None.
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SEE ALSO

211       link(),  rmdir(),  symlink(),  unlink(), the Base Definitions volume of
212       IEEE Std 1003.1-2001, <stdio.h>
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215       Portions of this text are reprinted and reproduced in  electronic  form
216       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
217       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
218       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
219       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
220       event of any discrepancy between this version and the original IEEE and
221       The Open Group Standard, the original IEEE and The Open Group  Standard
222       is  the  referee document. The original Standard can be obtained online
223       at http://www.opengroup.org/unix/online.html .
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227IEEE/The Open Group                  2003                           RENAME(3P)
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