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.TH scan_base64 3
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.SH NAME
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scan_base64 \- decode base64 encoded data
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.SH SYNTAX
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.B #include <libowfat/textcode.h>
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size_t \fBscan_base64\fP(const char *\fIsrc\fR,char *\fIdest\fR,size_t* \fIdestlen\fR);
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.SH DESCRIPTION
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scan_base64 decodes base64 encoded data from src into dest.
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It will stop when it encountes any non-valid input characters.
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It will then write the number of decoded bytes in dest into *destlen,
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and return the number of bytes decoded from src.
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Note that real world base64 encoded data is sometimes permitted to
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contain whitespace characters or new lines. This function will not allow
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those and return the decoded data until then.
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base64 works by taking 3 bytes of binary input and converting them into
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4 bytes of printable ASCII. If the input ends in the middle of a base64
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4-byte-tuple, scan_base64 will disregard the whole tuple.
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Many base64 variants demand padding in the last block. Some don't. This
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implementation will consume padding if it is there, but will not
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complain if it is not.
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dest can be NULL. destlen can be NULL.
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.SH "RETURN VALUE"
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scan_base64 returns the number of bytes successfully scanned and
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processed from src.
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.SH EXAMPLES
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scan_base64("%9FYO<F0`",buf,&i) -> return 8, i=5, buf="fnord"
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.SH "SEE ALSO"
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scan_xlong(3), scan_8long(3), fmt_ulong(3)
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