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This allowed me to standardize the sourcetar and sf/* scripts: the base
directory (containing ./git) is now empty, except for maintenance scripts,
while the source files and build scripts of the annotations are stored in
a subdirectory of their own.
37 lines
1.6 KiB
Text
37 lines
1.6 KiB
Text
Although not every tt(istream) object supports i(repositioning), some do. This
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means that it is possible to read the same section of a stream
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repeatedly. Repositioning is frequently used in emi(database applications)
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where it must be possible to access the information in the database randomly.
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The current position can be obtained and modified using the following members:
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itemization(
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ithtq(tellg)(ios::pos_type tellg())
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(hi(pos_type)the stream's current (absolute) position where the
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stream's next read-operation will take place is returned.)
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ithtq(seekg)
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(istream &seekg(ios::off_type step, ios::seekdir org))
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(modifies a stream's actual position. The function expects an
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ti(off_type) tt(step) representing the number of bytes the current stream
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position is moved with respect to tt(org). The tt(step) value may be negative,
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zero or positive.
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The origin of the step, tt(org) is a value in the
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hi(seekdir)tt(ios::seekdir) enumeration. Its values are:
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itemization(
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ithtq(beg)(ios::beg)
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(the stepsize is computed relative to the beginning of the
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stream. This value is used by default.
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)
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ithtq(cur)(ios::cur)
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(the stepsize is computed relative to the current position of the
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stream (as returned by tt(tellp)).
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)
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ithtq(end)(ios::end)
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(the stepsize is interpreted relative to the current end position
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of the the stream.)
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)
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It is OK to hi(seek beyond file boundaries) seek beyond the last file
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position. Seeking before tt(ios::beg) raises the hi(failbit)tt(ios::failbit)
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flag.
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)
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)
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