3 gzip Decompression
The
file/gunzip library provides
utilities to decompress archive files in
gzip format, or simply
to deccompress data using the
pkzip “inflate” method.
Extracts data that was compressed using the
gzip utility (or
gzip function), writing the uncompressed data directly to a
file. The
file argument is the name of the file containing
compressed data. The default output file name is the original name of
the compressed file as stored in
file. If a file by this name
exists, it will be overwritten. If no original name is stored in the
source file,
"unzipped" is used as the default output file
name.
The output-name-filter procedure is applied to two
arguments—the default destination file name and a boolean that is
#t if this name was read from file—before the
destination file is created. The return value of the file is used as
the actual destination file name (to be opened with the
'truncate flag of open-output-file).
If the compressed data turns out to be corrupted, the
exn:fail exception is raised.
Reads the port in for compressed data that was created using
the gzip utility, writing the uncompressed data to the port
out.
If the compressed data turns out to be corrupted, the
exn:fail exception is raised. The unzipping process may peek
further into in than needed to decompress the data, but it
will not consume the unneeded bytes.
Reads pkzip-format “deflated” data from the port in
and writes the uncompressed (“inflated”) data to the port
out. The data in a file created by gzip uses this
format (preceded with some header information).
If the compressed data turns out to be corrupted, the
exn:fail exception is raised. The inflate process may peek
further into in than needed to decompress the data, but it
will not consume the unneeded bytes.