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< title > FatFs - f_printf< / title >
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< body >
< div class = "para func" >
< h2 > f_printf< / h2 >
< p > The f_printf function writes formatted string to the file.< / p >
< pre >
int f_printf (
FIL* < span class = "arg" > fp< / span > , < span class = "c" > /* [IN] File object */< / span >
const TCHAR* < span class = "arg" > fmt< / span > , < span class = "c" > /* [IN] Format stirng */< / span >
...
);
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< / div >
< div class = "para arg" >
< h4 > Parameters< / h4 >
< dl class = "par" >
< dt > fp< / dt >
< dd > Pointer to the open file object structure.< / dd >
< dt > fmt< / dt >
< dd > Pointer to the null terminated format string. The terminator charactor will not be written.< / dd >
< dt > ...< / dt >
< dd > Optional arguments...< / dd >
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< / div >
< div class = "para ret" >
< h4 > Return Values< / h4 >
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< p > When the function succeeded, it returns number of characters written. If the function could not write the generated string to the file due to disk full or an error, < tt > EOF (-1)< / tt > will be returned.< / p >
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< / div >
< div class = "para desc" >
< h4 > Description< / h4 >
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< p > The format control directive is a sub-set of standard library shown as follos:< / p >
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< ul >
< li > Type: < tt > c C s S d D u U x X b B< / tt > < / li >
< li > Size: < tt > l L< / tt > < / li >
< li > Flag: < tt > 0 -< / tt > < / li >
< / ul >
< / div >
< div class = "para comp" >
< h4 > QuickInfo< / h4 >
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< p > This is a wrapper function of < a href = "write.html" > < tt > f_write< / tt > < / a > function. Available when < tt > _FS_READONLY == 0< / tt > and < tt > _USE_STRFUNC< / tt > is 1 or 2. When it is set to 2, < tt > '\n'< / tt > s contained in the output are converted to < tt > '\r'+'\n'< / tt > .< / p >
< p > When FatFs is configured to Unicode API (< tt > _LFN_UNICODE == 1< / tt > ), data types on the srting fuctions, < tt > f_putc< / tt > , < tt > f_puts< / tt > , < tt > f_printf< / tt > and < tt > f_gets< / tt > function, is also switched to Unicode. The character encoding on the file to be read/written via those functions is selected by < tt > _STRF_ENCODE< / tt > option.< / p >
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< / div >
< div class = "para use" >
< h4 > Example< / h4 >
< pre >
f_printf(& fil, "%d", 1234); < span class = "c" > /* "1234" */< / span >
f_printf(& fil, "%6d,%3d%%", -200, 5); < span class = "c" > /* " -200, 5%" */< / span >
f_printf(& fil, "%ld", 12345L); < span class = "c" > /* "12345" */< / span >
f_printf(& fil, "%06d", 25); < span class = "c" > /* "000025" */< / span >
f_printf(& fil, "%06d", -25); < span class = "c" > /* "000-25" */< / span >
f_printf(& fil, "%-6d", 25); < span class = "c" > /* "25 " */< / span >
f_printf(& fil, "%u", -1); < span class = "c" > /* "65535" or "4294967295" */< / span >
f_printf(& fil, "%04x", 0xAB3); < span class = "c" > /* "0ab3" */< / span >
f_printf(& fil, "%08LX", 0x123ABCL); < span class = "c" > /* "00123ABC" */< / span >
f_printf(& fil, "%016b", 0x550F); < span class = "c" > /* "0101010100001111" */< / span >
f_printf(& fil, "%s", "String"); < span class = "c" > /* "String" */< / span >
f_printf(& fil, "%8s", "abc"); < span class = "c" > /* " abc" */< / span >
f_printf(& fil, "%-8s", "abc"); < span class = "c" > /* "abc " */< / span >
f_printf(& fil, "%c", 'a'); < span class = "c" > /* "a" */< / span >
f_printf(& fil, "%f", 10.0); < span class = "c" > /* f_printf lacks floating point support */< / span >
< / pre >
< / div >
< div class = "para ref" >
< h4 > See Also< / h4 >
< p > < tt > < a href = "open.html" > f_open< / a > , < a href = "putc.html" > f_putc< / a > , < a href = "puts.html" > f_puts< / a > , < a href = "gets.html" > f_gets< / a > , < a href = "close.html" > f_close< / a > , < a href = "sfile.html" > FIL< / a > < / tt > < / p >
< / div >
< p class = "foot" > < a href = "../00index_e.html" > Return< / a > < / p >
< / body >
< / html >
