NAME

zopen — open a gzip compressed stream

LIBRARY

Compression Library (libz, -lz)

SYNOPSIS

FILE *
zopen(const char *path, const char *mode);

FILE *
zdopen(int fd, const char *mode);

DESCRIPTION

The zopen() function opens a gzip file whose name is the string pointed to by path and returns a stream which can be used to access the uncompressed contents of the file. The zdopen() variant takes a gzip file referenced by the file descriptor fd, analogous to fdopen(3). They are wrappers around zlib(3) and the standard stream I/O APIs.

The argument mode has the same meaning as it does in fopen(3).

The zopen() and zdopen() functions will associate the read, write, seek and close functions of zlib(3) with the returned stream.

RETURN VALUES

Upon successful completion zopen() and zdopen() return a FILE pointer. Otherwise, NULL is returned and the global variable errno is set to indicate the error.

ERRORS

In addition to the errors documented for fopen(3) and fdopen(3), the functions may also fail for:

[ENOMEM]: Insufficient memory is available.

COMPATIBILITY

The implementation of zopen() function first appeared in NetBSD 1.6 and FreeBSD 4.5. zdopen() first appeared in FreeBSD 13.0. These functions may not be portable to systems other than FreeBSD.