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< link rel = "up" title = "FatFs" href = "../00index_e.html" >
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< title > FatFs - f_read< / title >
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< div class = "para func" >
< h2 > f_read< / h2 >
< p > The f_read function reads data from a file.< / p >
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FRESULT f_read (
FIL* < span class = "arg" > fp< / span > , < span class = "c" > /* [IN] File object */< / span >
void* < span class = "arg" > buff< / span > , < span class = "c" > /* [OUT] Buffer to store read data */< / span >
UINT < span class = "arg" > btr< / span > , < span class = "c" > /* [IN] Number of bytes to read */< / span >
UINT* < span class = "arg" > br< / span > < span class = "c" > /* [OUT] Number of bytes read */< / span >
);
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< div class = "para arg" >
< h4 > Parameters< / h4 >
< dl class = "par" >
< dt > fp< / dt >
< dd > Pointer to the open file object.< / dd >
< dt > buff< / dt >
< dd > Pointer to the buffer to store read data.< / dd >
< dt > btr< / dt >
< dd > Number of bytes to read in range of < tt > UINT< / tt > type.< / dd >
< dt > br< / dt >
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< dd > Pointer to the < tt > UINT< / tt > variable to return number of bytes read. This value is always valid after the function call regardless of the return value.< / dd >
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< div class = "para ret" >
< h4 > Return Values< / h4 >
< p >
< a href = "rc.html#ok" > FR_OK< / a > ,
< a href = "rc.html#de" > FR_DISK_ERR< / a > ,
< a href = "rc.html#ie" > FR_INT_ERR< / a > ,
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< a href = "rc.html#dn" > FR_DENIED< / a > ,
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< a href = "rc.html#io" > FR_INVALID_OBJECT< / a > ,
< a href = "rc.html#tm" > FR_TIMEOUT< / a >
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< div class = "para desc" >
< h4 > Description< / h4 >
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< p > The function starts to read data from the file at the position pointed by the read/write pointer. The read/write pointer advances as number of bytes read. After the function succeeded, < tt class = "arg" > *br< / tt > should be checked to detect end of the file. In case of < tt class = "arg" > *br< / tt > < < tt class = "arg" > btr< / tt > , it means the read/write pointer reached end of the file during read operation.< / p >
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< div class = "para comp" >
< h4 > QuickInfo< / h4 >
< p > Always available.< / p >
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< div class = "para ref" >
< h4 > See Also< / h4 >
< p > < tt > < a href = "open.html" > f_open< / a > , < a href = "gets.html" > fgets< / a > , < a href = "write.html" > f_write< / a > , < a href = "close.html" > f_close< / a > , < a href = "sfile.html" > FIL< / a > < / tt > < / p >
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< p class = "foot" > < a href = "../00index_e.html" > Return< / a > < / p >
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