diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | gzopen.3 | 84 |
2 files changed, 83 insertions, 2 deletions
diff --git a/Makefile b/Makefile index 8975efd..9a75d20 100644 --- a/Makefile +++ b/Makefile @@ -41,6 +41,7 @@ MAN += zlibVersion.3 MLINKS += adler32.3 adler32_z.3 MLINKS += compress.3 compress2.3 MLINKS += crc32.3 crc32_z.3 +MLINKS += gzopen.3 gzdopen.3 MLINKS += inflateReset.3 inflateReset2.3 MLINKS += uncompress.3 uncompress2.3 diff --git a/gzopen.3 b/gzopen.3 index 37ed629..daebe5a 100644 --- a/gzopen.3 +++ b/gzopen.3 @@ -3,7 +3,8 @@ .Os . .Sh NAME -.Nm gzopen +.Nm gzopen , +.Nm gzdopen .Nd open gzip file . .Sh LIBRARY @@ -13,6 +14,8 @@ .In zlib.h .Ft gzFile .Fn gzopen "const char *path" "const char *mode" +.Ft gzFile +.Fn gzdopen "int fd" "const char *mode" . .Sh DESCRIPTION Opens a gzip (.gz) file @@ -111,9 +114,70 @@ When reading, this will be detected automatically by looking for the magic two-byte gzip header. . +.Pp +.Fn gzdopen +associates at +.Vt gzFile +with the file descriptor +.Fa fd . +File descriptors +are obtained from calls like +.Xr open 2 , +.Xr dup 2 , +.Xr creat 2 , +.Xr pipe 2 +or +.Xr fileno 3 +.Po +if the file has been previously opened with +.Xr fopen 3 +.Pc . +The +.Fa mode +parameter is as in +.Fn gzopen . +. +.Pp +The next call of +.Xr gzclose 3 +on the returned +.Vt gzFile +will also close the file descriptor +.Fa fd , +just like +.Xr fclose 3 . +If you want to keep +.Fa fd +open, +use +.Li "fd = dup(fd_keep); gz = gzdopen(fd, mode);" . +The duplicated descriptor should be saved +to avoid a leak, +since +.Fn gzdopen +does not close +.Fa fd +if it fails. +If you are using +.Xr fileno 3 +to get the file descriptor from a +.Vt FILE * , +then you will have to use +.Xr dup 2 +to avoid double-closing +the file descriptor. +Both +.Xr gzclose 3 +and +.Xr flcose 3 +will close the associated file descriptor, +so they need to have different file descriptors. +. .Sh RETURN VALUES .Fn gzopen -returns +and +.Fn gzdopen +return .Dv NULL if the file could not be opened, if there was insufficient memory @@ -133,6 +197,22 @@ was not provided, or .Sq + was provided +.Pc , +or if +.Fa fd +is -1. +The file descriptor +is not used until the next +gz* read, write, seek, or close operation, +so +.Fn gzdopen +will not detect if +.Fa fd +is invalid +.Po +unless +.Fa fd +is -1 .Pc . .Va errno can be checked |