NAME

       ns_zlib - Zlib compression support

SYNOPSIS

       ns_zlib compress string
       ns_zlib gunzip file
       ns_zlib gzip string
       ns_zlib gzipfile file
       ns_zlib uncompress string
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DESCRIPTION

       The  ns_zlib  command  enables  compressing  and  uncompressing  of strings or files.  The
       command is available if the nszlib.so module is loaded into AOLserver or the libnszlib.so,
       nszlib.dll,  or  libnszlib.dylib  dynamic  library  is  loaded using the load command in a
       suitable tclsh such as nstclsh.

       ns_zlib compress string
              This command compresses the given string and returns a Tcl byte array  object  with
              the compressed data.

       ns_zlib gunzip file
              This  command  uncompresses  the  contents  of the given gzipped file and returns a
              string as the result.

       ns_zlib gzipfile file
              This command is similar to the gzip shell routines, compressing the given file into
              a  new  file with the .gz extension.  If successful, the original uncompressed file
              is deleted.

       ns_zlib uncompress bytearray
              This command takes a byte array object which includes compressed data  and  returns
              an uncompressed string object.

EXAMPLES

       The following examples demonstrate compressing and uncompressing a string;

              # Compress Tcl string
              set test "This is test string"
              set data [ns_zlib compress $test]
              set test [ns_zlib uncompress $data]
              --> returns "This is test string"

              # Compress the string into gzip format
              set gzip [ns_zlib gzip $test]

              # Save as gzip file
              set fd [open /tmp/test.gz w]
              fconfigure $fd -translation binary -encoding binary
              puts -nonewline $fd $gzip
              close $fd

              # Uncompress gzipped file
              set test [ns_zlib gunzip /tmp/test.gz]
              --> returns "This is test string"

SEE ALSO

       ns_adp_ctl(n), load(n)

KEYWORDS

       GZIP, compress, uncompress