48 lines
1.4 KiB
Groff
48 lines
1.4 KiB
Groff
.Dd March 11, 2017
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.Dt SQLITE3_BLOB_READ 3
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.Os
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.Sh NAME
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.Nm sqlite3_blob_read
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.Nd Read Data From A BLOB Incrementally
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.Sh SYNOPSIS
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.Ft int
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.Fo sqlite3_blob_read
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.Fa "sqlite3_blob *"
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.Fa "void *Z"
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.Fa "int N"
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.Fa "int iOffset"
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.Fc
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.Sh DESCRIPTION
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This function is used to read data from an open BLOB handle
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into a caller-supplied buffer.
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N bytes of data are copied into buffer Z from the open BLOB, starting
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at offset iOffset.
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.Pp
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If offset iOffset is less than N bytes from the end of the BLOB, SQLITE_ERROR
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is returned and no data is read.
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If N or iOffset is less than zero, SQLITE_ERROR is returned
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and no data is read.
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The size of the blob (and hence the maximum value of N+iOffset) can
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be determined using the sqlite3_blob_bytes() interface.
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.Pp
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An attempt to read from an expired BLOB handle fails with
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an error code of SQLITE_ABORT.
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.Pp
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On success, sqlite3_blob_read() returns SQLITE_OK.
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Otherwise, an error code or an extended error code
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is returned.
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.Pp
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This routine only works on a BLOB handle which has been
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created by a prior successful call to sqlite3_blob_open()
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and which has not been closed by sqlite3_blob_close().
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Passing any other pointer in to this routine results in undefined and
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probably undesirable behavior.
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.Pp
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.Sh SEE ALSO
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.Xr sqlite3_blob 3 ,
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.Xr sqlite3_blob_bytes 3 ,
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.Xr sqlite3_blob_close 3 ,
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.Xr sqlite3_blob_open 3 ,
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.Xr sqlite3_blob_write 3 ,
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.Xr SQLITE_OK 3
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