Why does the gzdeflate PHP function not work in Customer Portal?

Environment:

Connect for PHP, Customer Portal
Oracle B2C Service

Resolution:

The Zlib PHP library is not included in the product, and therefore none the functions included in the Zlib library will work with Customer Portal.

Zlib Functions
deflate_add — Incrementally deflate data
deflate_init — Initialize an incremental deflate context
gzclose — Close an open gz-file pointer
gzcompress — Compress a string
gzdecode — Decodes a gzip compressed string
gzdeflate — Deflate a string
gzencode — Create a gzip compressed string
gzeof — Test for EOF on a gz-file pointer
gzfile — Read entire gz-file into an array
gzgetc — Get character from gz-file pointer
gzgets — Get line from file pointer
gzgetss — Get line from gz-file pointer and strip HTML tags
gzinflate — Inflate a deflated string
gzopen — Open gz-file
gzpassthru — Output all remaining data on a gz-file pointer
gzputs — Alias of gzwrite
gzread — Binary-safe gz-file read
gzrewind — Rewind the position of a gz-file pointer
gzseek — Seek on a gz-file pointer
gztell — Tell gz-file pointer read/write position
gzuncompress — Uncompress a compressed string
gzwrite — Binary-safe gz-file write
inflate_add — Incrementally inflate encoded data
inflate_get_read_len — Get number of bytes read so far
inflate_get_status — Get decompression status
inflate_init — Initialize an incremental inflate context
readgzfile — Output a gz-file
zlib_decode — Uncompress any raw/gzip/zlib encoded data
zlib_encode — Compress data with the specified encoding
zlib_get_coding_type — Returns the coding type used for output compression