diff options
Diffstat (limited to 'doc/zlib.n')
| -rw-r--r-- | doc/zlib.n | 89 |
1 files changed, 32 insertions, 57 deletions
@@ -47,37 +47,23 @@ have been in gzip format. If \fB\-headerVar\fR is given, store a dictionary describing the contents of the gzip header in the variable called \fIvarName\fR. The keys of the dictionary that may be present are: .RS -.TP -\fBcomment\fR -. +.IP \fBcomment\fR The comment field from the header, if present. -.TP -\fBcrc\fR -. +.IP \fBcrc\fR A boolean value describing whether a CRC of the header is computed. -.TP -\fBfilename\fR -. +.IP \fBfilename\fR The filename field from the header, if present. -.TP -\fBos\fR -. +.IP \fBos\fR The operating system type code field from the header (if not the QW unknown value). See RFC 1952 for the meaning of these codes. -.TP -\fBsize\fR -. +.IP \fBsize\fR The size of the uncompressed data. -.TP -\fBtime\fR -. +.IP \fBtime\fR The time field from the header if non-zero, expected to be time that the file named by the \fBfilename\fR field was modified. Suitable for use with \fBclock format\fR. -.TP -\fBtype\fR -. +.IP \fBtype\fR The type of the uncompressed data (\fBbinary\fR or \fBtext\fR) if known. .RE .TP @@ -89,33 +75,21 @@ If \fB\-level\fR is given, \fIlevel\fR gives the compression level to use is given, \fIdict\fR is a dictionary containing values used for the gzip header. The following keys may be defined: .RS -.TP -\fBcomment\fR -. +.IP \fBcomment\fR Add the given comment to the header of the gzip-format data. -.TP -\fBcrc\fR -. +.IP \fBcrc\fR A boolean saying whether to compute a CRC of the header. Note that if the data is to be interchanged with the \fBgzip\fR program, a header CRC should \fInot\fR be computed. -.TP -\fBfilename\fR -. +.IP \fBfilename\fR The name of the file that the data to be compressed came from. -.TP -\fBos\fR -. +.IP \fBos\fR The operating system type code, which should be one of the values described in RFC 1952. -.TP -\fBtime\fR -. +.IP \fBtime\fR The time that the file named in the \fBfilename\fR key was last modified. This will be in the same as is returned by \fBclock seconds\fR or \fBfile mtime\fR. -.TP -\fBtype\fR -. +.IP \fBtype\fR The type of the data being compressed, being \fBbinary\fR or \fBtext\fR. .RE .TP @@ -134,34 +108,22 @@ The transformation can be removed again with \fBchan pop\fR. The \fImode\fR argument determines what type of transformation is pushed; the following are supported: .RS -.TP -\fBcompress\fR -. +.IP \fBcompress\fR The transformation will be a compressing transformation that produces zlib-format data on \fIchannel\fR, which must be writable. -.TP -\fBdecompress\fR -. +.IP \fBdecompress\fR The transformation will be a decompressing transformation that reads zlib-format data from \fIchannel\fR, which must be readable. -.TP -\fBdeflate\fR -. +.IP \fBdeflate\fR The transformation will be a compressing transformation that produces raw compressed data on \fIchannel\fR, which must be writable. -.TP -\fBgunzip\fR -. +.IP \fBgunzip\fR The transformation will be a decompressing transformation that reads gzip-format data from \fIchannel\fR, which must be readable. -.TP -\fBgzip\fR -. +.IP \fBgzip\fR The transformation will be a compressing transformation that produces gzip-format data on \fIchannel\fR, which must be writable. -.TP -\fBinflate\fR -. +.IP \fBinflate\fR The transformation will be a decompressing transformation that reads raw compressed data from \fIchannel\fR, which must be readable. .PP @@ -169,6 +131,7 @@ The following options may be set when creating a transformation via the .QW "\fIoptions ...\fR" to the \fBzlib push\fR command: +.\" OPTION: -dictionary .TP \fB\-dictionary\fI binData\fR .VS "TIP 400" @@ -180,16 +143,19 @@ with the most commonly used strings preferably put towards the end of the dictionary. Tcl provides no mechanism for choosing a good such dictionary for a particular data sequence. .VE +.\" OPTION: -header .TP \fB\-header\fI dictionary\fR . Passes a description of the gzip header to create, in the same format that \fBzlib gzip\fR understands. +.\" OPTION: -level .TP \fB\-level\fI compressionLevel\fR . How hard to compress the data. Must be an integer from 0 (uncompressed) to 9 (maximally compressed). +.\" OPTION: -limit .TP \fB\-limit\fI readaheadLimit\fR . @@ -209,6 +175,7 @@ to further readers. Both compressing and decompressing channel transformations add extra configuration options that may be accessed through \fBchan configure\fR. The options are: +.\" OPTION: -checksum .TP \fB\-checksum\fI checksum\fR . @@ -216,6 +183,7 @@ This read-only option gets the current checksum for the uncompressed data that the compression engine has seen so far. It is valid for both compressing and decompressing transforms, but not for the raw inflate and deflate formats. The compression algorithm depends on what format is being produced or consumed. +.\" OPTION: -dictionary .TP \fB\-dictionary\fI binData\fR .VS "TIP 400" @@ -227,6 +195,7 @@ the transformation is stacked. Note that this cannot be used to get the current active compression dictionary mid-stream, as that information is not exposed by the underlying library. .VE +.\" OPTION: -flush .TP \fB\-flush\fI type\fR . @@ -236,12 +205,14 @@ underlying channel. It is only valid for compressing transformations. The expensive flush respectively. Flushing degrades the compression ratio, but makes it easier for a decompressor to recover more of the file in the case of data corruption. +.\" OPTION: -header .TP \fB\-header\fI dictionary\fR . This read-only option, only valid for decompressing transforms that are processing gzip-format data, returns the dictionary describing the header read off the data stream. +.\" OPTION: -limit .TP \fB\-limit\fI readaheadLimit\fR . @@ -386,12 +357,14 @@ buffers while applying the transformation. The following \fIoption\fRs are supported (or an unambiguous prefix of them), which are used to modify the way in which the transformation is applied: .RS +.\" OPTION: -dictionary .TP \fB\-dictionary\fI binData\fR .VS "TIP 400" Sets the compression dictionary to use when working with compressing or decompressing the data to be \fIbinData\fR. .VE +.\" OPTION: -finalize .TP \fB\-finalize\fR . @@ -405,6 +378,7 @@ of the stream with the \fBget\fR subcommand. This option is mutually exclusive with the \fB\-flush\fR and \fB\-fullflush\fR options. .RE +.\" OPTION: -flush .TP \fB\-flush\fR . @@ -416,6 +390,7 @@ compressed so far, at some performance penalty. This option is mutually exclusive with the \fB\-finalize\fR and \fB\-fullflush\fR options. .RE +.\" OPTION: -fullflush .TP \fB\-fullflush\fR . |