fileutils.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

<refentry id="glib-File-Utilities">
<refmeta>
<refentrytitle>File Utilities</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>GLIB Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>File Utilities</refname><refpurpose>various file-related functions.</refpurpose>
</refnamediv>

<refsynopsisdiv><title>Synopsis</title>
<synopsis>

#include &lt;glib.h&gt;


enum        <link linkend="GFileError">GFileError</link>;
#define     <link linkend="G-FILE-ERROR-CAPS">G_FILE_ERROR</link>
enum        <link linkend="GFileTest">GFileTest</link>;
<link linkend="GFileError">GFileError</link>  <link linkend="g-file-error-from-errno">g_file_error_from_errno</link>         (<link linkend="gint">gint</link> err_no);
<link linkend="gboolean">gboolean</link>    <link linkend="g-file-get-contents">g_file_get_contents</link>             (const <link linkend="gchar">gchar</link> *filename,
                                             <link linkend="gchar">gchar</link> **contents,
                                             <link linkend="gsize">gsize</link> *length,
                                             <link linkend="GError">GError</link> **error);
<link linkend="gboolean">gboolean</link>    <link linkend="g-file-test">g_file_test</link>                     (const <link linkend="gchar">gchar</link> *filename,
                                             <link linkend="GFileTest">GFileTest</link> test);
int         <link linkend="g-mkstemp">g_mkstemp</link>                       (char *tmpl);
int         <link linkend="g-file-open-tmp">g_file_open_tmp</link>                 (const char *tmpl,
                                             char **name_used,
                                             <link linkend="GError">GError</link> **error);

struct      <link linkend="GDir">GDir</link>;
<link linkend="GDir">GDir</link>*       <link linkend="g-dir-open">g_dir_open</link>                      (const <link linkend="gchar">gchar</link> *path,
                                             <link linkend="guint">guint</link> flags,
                                             <link linkend="GError">GError</link> **error);
G_CONST_RETURN <link linkend="gchar">gchar</link>* <link linkend="g-dir-read-name">g_dir_read_name</link>       (<link linkend="GDir">GDir</link> *dir);
void        <link linkend="g-dir-rewind">g_dir_rewind</link>                    (<link linkend="GDir">GDir</link> *dir);
void        <link linkend="g-dir-close">g_dir_close</link>                     (<link linkend="GDir">GDir</link> *dir);

</synopsis>
</refsynopsisdiv>





<refsect1>
<title>Description</title>
<para>

</para>
</refsect1>

<refsect1>
<title>Details</title>
<refsect2>
<title><anchor id="GFileError">enum GFileError</title>
<programlisting>typedef enum
{
  G_FILE_ERROR_EXIST,
  G_FILE_ERROR_ISDIR,
  G_FILE_ERROR_ACCES,
  G_FILE_ERROR_NAMETOOLONG,
  G_FILE_ERROR_NOENT,
  G_FILE_ERROR_NOTDIR,
  G_FILE_ERROR_NXIO,
  G_FILE_ERROR_NODEV,
  G_FILE_ERROR_ROFS,
  G_FILE_ERROR_TXTBSY,
  G_FILE_ERROR_FAULT,
  G_FILE_ERROR_LOOP,
  G_FILE_ERROR_NOSPC,
  G_FILE_ERROR_NOMEM,
  G_FILE_ERROR_MFILE,
  G_FILE_ERROR_NFILE,
  G_FILE_ERROR_BADF,
  G_FILE_ERROR_INVAL,
  G_FILE_ERROR_PIPE,
  G_FILE_ERROR_AGAIN,
  G_FILE_ERROR_INTR,
  G_FILE_ERROR_IO,
  G_FILE_ERROR_PERM,
  G_FILE_ERROR_FAILED
} GFileError;
</programlisting>
<para>
Values corresponding to <literal>errno</literal> codes returned from file operations
on UNIX. Unlike <literal>errno</literal> codes, <link linkend="GFileError">GFileError</link> values are available on 
all systems, even Windows. The exact meaning of each code depends on what
sort of file operation you were performing; the UNIX documentation
gives more details. The following error code descriptions come 
from the GNU C Library manual, and are under the copyright
of that manual.
</para>

<para>
It's not very portable to make detailed assumptions about exactly
which errors will be returned from a given operation. Some errors
don't occur on some systems, etc., sometimes there are subtle
differences in when a system will report a given error, etc.
</para><informaltable pgwide="1" frame="none" role="enum">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row>
<entry><literal>G_FILE_ERROR_EXIST</literal></entry>
<entry>Operation not permitted; only the owner of the
     file (or other resource) or processes with special privileges can
     perform the operation.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_ISDIR</literal></entry>
<entry>File is a directory; you cannot open a directory
     for writing, or create or remove hard links to it.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_ACCES</literal></entry>
<entry>Permission denied; the file permissions do not
     allow the attempted operation.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NAMETOOLONG</literal></entry>
<entry>Filename too long.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NOENT</literal></entry>
<entry>No such file or directory.  This is a "file
     doesn't exist" error for ordinary files that are referenced in
     contexts where they are expected to already exist.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NOTDIR</literal></entry>
<entry>A file that isn't a directory was specified when
     a directory is required.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NXIO</literal></entry>
<entry>No such device or address.  The system tried to
     use the device represented by a file you specified, and it
     couldn't find the device.  This can mean that the device file was
     installed incorrectly, or that the physical device is missing or
     not correctly attached to the computer.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NODEV</literal></entry>
<entry>This file is of a type that doesn't support
     mapping.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_ROFS</literal></entry>
<entry>The directory containing the new link can't be
          modified because it's on a read-only file system.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_TXTBSY</literal></entry>
<entry>Text file busy.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_FAULT</literal></entry>
<entry>You passed in a pointer to bad memory.
  (GLib won't reliably return this, don't pass in pointers to bad
  memory.)
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_LOOP</literal></entry>
<entry>Too many levels of symbolic links were encountered
  in looking up a file name.  This often indicates a cycle of symbolic
  links.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NOSPC</literal></entry>
<entry>No space left on device; write operation on a
  file failed because the disk is full.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NOMEM</literal></entry>
<entry>No memory available.  The system cannot allocate
     more virtual memory because its capacity is full.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_MFILE</literal></entry>
<entry>The current process has too many files open and
     can't open any more.  Duplicate descriptors do count toward this
     limit.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_NFILE</literal></entry>
<entry>There are too many distinct file openings in the
     entire system.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_BADF</literal></entry>
<entry>Bad file descriptor; for example, I/O on a
     descriptor that has been closed or reading from a descriptor open
     only for writing (or vice versa).
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_INVAL</literal></entry>
<entry>Invalid argument.  This is used to indicate
     various kinds of problems with passing the wrong argument to a
     library function.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_PIPE</literal></entry>
<entry>Broken pipe; there is no process reading from the
     other end of a pipe.  Every library function that returns this
     error code also generates a `SIGPIPE' signal; this signal
     terminates the program if not handled or blocked.  Thus, your
     program will never actually see this code unless it has handled or
     blocked `SIGPIPE'.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_AGAIN</literal></entry>
<entry>Resource temporarily unavailable; the call might
     work if you try again later.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_INTR</literal></entry>
<entry>Interrupted function call; an asynchronous signal
     occurred and prevented completion of the call.  When this
     happens, you should try the call again.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_IO</literal></entry>
<entry>Input/output error; usually used for physical read
    or write errors. i.e. the disk or other physical device hardware
    is returning errors.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_PERM</literal></entry>
<entry>Operation not permitted; only the owner of the
     file (or other resource) or processes with special privileges can
     perform the operation.
</entry>
</row>
<row>
<entry><literal>G_FILE_ERROR_FAILED</literal></entry>
<entry>Does not correspond to a UNIX error code; this
  is the standard "failed for unspecified reason" error code present in 
  all <link linkend="GError">GError</link> error code enumerations. Returned if no specific
  code applies.

</entry>
</row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-FILE-ERROR-CAPS">G_FILE_ERROR</title>
<programlisting>#define G_FILE_ERROR g_file_error_quark ()
</programlisting>
<para>
Error domain for file operations. Errors in this domain will
be from the <link linkend="GFileError">GFileError</link> enumeration. See <link linkend="GError">GError</link> for information on 
error domains.
</para></refsect2>
<refsect2>
<title><anchor id="GFileTest">enum GFileTest</title>
<programlisting>typedef enum
{
  G_FILE_TEST_IS_REGULAR    = 1 &lt;&lt; 0,
  G_FILE_TEST_IS_SYMLINK    = 1 &lt;&lt; 1,
  G_FILE_TEST_IS_DIR        = 1 &lt;&lt; 2,
  G_FILE_TEST_IS_EXECUTABLE = 1 &lt;&lt; 3,
  G_FILE_TEST_EXISTS        = 1 &lt;&lt; 4
} GFileTest;
</programlisting>
<para>
A test to perform an a file using <link linkend="g-file-test">g_file_test</link>().
</para><informaltable pgwide="1" frame="none" role="enum">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row>
<entry><literal>G_FILE_TEST_IS_REGULAR</literal></entry>