summaryrefslogtreecommitdiffstats
path: root/Doc/lib/libshutil.tex
blob: 449d7414f38b248d524c3e493cec04ef247f5567 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
\section{\module{shutil} ---
         High-level file operations}

\declaremodule{standard}{shutil}
\modulesynopsis{High-level file operations, including copying.}
\sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
% partly based on the docstrings


The \module{shutil} module offers a number of high-level operations on
files and collections of files.  In particular, functions are provided 
which support file copying and removal.
\index{file!copying}
\index{copying files}

\strong{Caveat:}  On MacOS, the resource fork and other metadata are
not used.  For file copies, this means that resources will be lost and 
file type and creator codes will not be correct.


\begin{funcdesc}{copyfile}{src, dst}
  Copy the contents of the file named \var{src} to a file named
  \var{dst}.  The destination location must be writable; otherwise, 
  an \exception{IOError} exception will be raised.
  If \var{dst} already exists, it will be replaced.  
  Special files such as character or block devices
  and pipes cannot be copied with this function.  \var{src} and
  \var{dst} are path names given as strings.
\end{funcdesc}

\begin{funcdesc}{copyfileobj}{fsrc, fdst\optional{, length}}
  Copy the contents of the file-like object \var{fsrc} to the
  file-like object \var{fdst}.  The integer \var{length}, if given,
  is the buffer size. In particular, a negative \var{length} value
  means to copy the data without looping over the source data in
  chunks; by default the data is read in chunks to avoid uncontrolled
  memory consumption.
\end{funcdesc}

\begin{funcdesc}{copymode}{src, dst}
  Copy the permission bits from \var{src} to \var{dst}.  The file
  contents, owner, and group are unaffected.  \var{src} and \var{dst}
  are path names given as strings.
\end{funcdesc}

\begin{funcdesc}{copystat}{src, dst}
  Copy the permission bits, last access time, and last modification
  time from \var{src} to \var{dst}.  The file contents, owner, and
  group are unaffected.  \var{src} and \var{dst} are path names given
  as strings.
\end{funcdesc}

\begin{funcdesc}{copy}{src, dst}
  Copy the file \var{src} to the file or directory \var{dst}.  If
  \var{dst} is a directory, a file with the same basename as \var{src} 
  is created (or overwritten) in the directory specified.  Permission
  bits are copied.  \var{src} and \var{dst} are path names given as
  strings.
\end{funcdesc}

\begin{funcdesc}{copy2}{src, dst}
  Similar to \function{copy()}, but last access time and last
  modification time are copied as well.  This is similar to the
  \UNIX{} command \program{cp} \programopt{-p}.
\end{funcdesc}

\begin{funcdesc}{copytree}{src, dst\optional{, symlinks}}
  Recursively copy an entire directory tree rooted at \var{src}.  The
  destination directory, named by \var{dst}, must not already exist;
  it will be created as well as missing parent directories.
  Permissions and times of directories are copied with \function{copystat()},
  individual files are copied using \function{copy2()}.  
  If \var{symlinks} is true, symbolic links in
  the source tree are represented as symbolic links in the new tree;
  if false or omitted, the contents of the linked files are copied to
  the new tree.  If exception(s) occur, an \exception{Error} is raised
  with a list of reasons.

  The source code for this should be considered an example rather than 
  a tool.

  \versionchanged[\exception{Error} is raised if any exceptions occur during
                  copying, rather than printing a message]{2.3}

  \versionchanged[Create intermediate directories needed to create \var{dst},
                  rather than raising an error. Copy permissions and times of
		  directories using \function{copystat()}]{2.5}

\end{funcdesc}

\begin{funcdesc}{rmtree}{path\optional{, ignore_errors\optional{, onerror}}}
  Delete an entire directory tree.\index{directory!deleting}
  If \var{ignore_errors} is true,
  errors resulting from failed removals will be ignored; if false or
  omitted, such errors are handled by calling a handler specified by
  \var{onerror} or, if that is omitted, they raise an exception.

  If \var{onerror} is provided, it must be a callable that accepts
  three parameters: \var{function}, \var{path}, and \var{excinfo}.
  The first parameter, \var{function}, is the function which raised
  the exception; it will be \function{os.listdir()}, \function{os.remove()} or
  \function{os.rmdir()}.  The second parameter, \var{path}, will be
  the path name passed to \var{function}.  The third parameter,
  \var{excinfo}, will be the exception information return by
  \function{sys.exc_info()}.  Exceptions raised by \var{onerror} will
  not be caught.
\end{funcdesc}

\begin{funcdesc}{move}{src, dst}
Recursively move a file or directory to another location.

If the destination is on our current filesystem, then simply use
rename.  Otherwise, copy src to the dst and then remove src.

\versionadded{2.3}
\end{funcdesc}

\begin{excdesc}{Error}
This exception collects exceptions that raised during a mult-file
operation. For \function{copytree}, the exception argument is a
list of 3-tuples (\var{srcname}, \var{dstname}, \var{exception}).

\versionadded{2.3}
\end{excdesc}

\subsection{Example \label{shutil-example}}

This example is the implementation of the \function{copytree()}
function, described above, with the docstring omitted.  It
demonstrates many of the other functions provided by this module.

\begin{verbatim}
def copytree(src, dst, symlinks=0):
    names = os.listdir(src)
    os.mkdir(dst)
    for name in names:
        srcname = os.path.join(src, name)
        dstname = os.path.join(dst, name)
        try:
            if symlinks and os.path.islink(srcname):
                linkto = os.readlink(srcname)
                os.symlink(linkto, dstname)
            elif os.path.isdir(srcname):
                copytree(srcname, dstname, symlinks)
            else:
                copy2(srcname, dstname)
        except (IOError, os.error), why:
            print "Can't copy %s to %s: %s" % (`srcname`, `dstname`, str(why))
\end{verbatim}