+static int write_compressed_tar_archive(struct archiver_args *args,const char *filter)
+{
+ int rw[2];
+ pid_t gzpid;
+ int stdout2;
+ int status;
+ int rv;
+
+ stdout2 = chk_non_negative(dup(STDIN_FILENO), "Preserving STDOUT before compressing");
+ chk_zero(pipe(rw), "Opening pipe from compressor subprocess");
+ gzpid = chk_non_negative(fork(), "Forking compressor subprocess");
+ if(gzpid==0) {
+ /* child */
+ chk_zero(close(rw[1]), "Closing write end of pipe in child");
+ chk_zero(close(STDIN_FILENO), "Closing STDIN");
+ chk_non_negative(dup2(rw[0],STDIN_FILENO), "Redirecting compressor input to stdin");
+ execlp(filter,filter,NULL);
+ _exit(-1);
+ }
+ /* parent */
+ chk_zero(close(rw[0]), "Closing read end of pipe");
+ chk_non_negative(dup2(rw[1],STDOUT_FILENO), "Redirecting output to compressor");
+
+ rv = write_tar_archive(args);
+
+ chk_zero(close(STDOUT_FILENO), "Closing STDOUT redirected to compressor");
+ chk_non_negative(dup2(stdout2,STDOUT_FILENO), "Restoring uncompressed STDOUT");
+ chk_zero(close(stdout2), "Closing uncompressed STDOUT");
+ chk_zero(close(rw[1]), "Closing write end of pipe in parent");
+ chk_positive(waitpid(gzpid,&status,0), "Waiting on compressor process");
+ if(! ( WIFEXITED(status) && WEXITSTATUS(status)==0 ) )
+ cgit_print_error("Failed to compress archive");
+
+ return rv;
+}
+