SYNOPSIS

#include <util/filter.h>

NEOERR *filter_create_fd(const char *cmd, int *fdin, int *fdout, int *fderr, 
                         pid_t *pid);

ARGUMENTS

cmd -> the sub command to execute. Will be executed with
/bin/sh -c
fdin -> pointer to return the stdin pipe, or NULL if you don't
want the stdin pipe
fdout -> pointer to return the stdout pipe, or NULL if you don't
want the stdout pipe
fderr -> pointer to return the stderr pipe, or NULL if you don't
want the stderr pipe

DESCRIPTION

filter_create_fd and filter_create_fp are what popen

been: a mechanism to create sub processes and have pipes to all their input/output. The concept was taken from mutt, though python has something similar with popen3/popen4. You control which pipes the function returns by the fdin/fdout/fderr arguments. A NULL value means "don't create a pipe", a pointer to an int will cause the pipes to be created and the value of the file descriptor stored in the int. You will have to close(2) the file descriptors yourself.

RETURN VALUE

fdin -> the stdin file descriptor of the sub process
fdout -> the stdout file descriptor of the sub process
fderr -> the stderr file descriptor of the sub process
pid -> the pid of the sub process