58 lines
1.2 KiB
Markdown
58 lines
1.2 KiB
Markdown
# PRFileDesc
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A file descriptor used to represent any open file, such as a normal
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file, an end point of a pipe, or a socket (end point of network
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communication).
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## Syntax
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```{code}
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#include <prio.h>
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struct PRFileDesc {
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PRIOMethods *methods;
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PRFilePrivate *secret;
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PRFileDesc *lower, *higher;
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void (*dtor)(PRFileDesc *fd);
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PRDescIdentity identity;
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};
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typedef struct PRFileDesc PRFileDesc;
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```
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### Parameters
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`methods`
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: The I/O methods table. See {ref}`PRIOMethods`.
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`secret`
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: Layer-dependent implementation data. See {ref}`PRFilePrivate`.
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`lower`
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: Pointer to lower layer.
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`higher`
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: Pointer to higher layer.
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`dtor`
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: A destructor function for the layer.
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`identity`
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: Identity of this particular layer. See {ref}`PRDescIdentity`.
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## Description
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The fields of this structure are significant only if you are
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implementing a layer on top of NSPR, such as SSL. Otherwise, you use
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functions such as {ref}`PR_Open` and {ref}`PR_NewTCPSocket` to obtain a file
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descriptor, which you should treat as an opaque structure.
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For more details about the use of {ref}`PRFileDesc` and related structures,
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see [File Descriptor Types](I_O_Types#File_Descriptor_Types).
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