C :: Redirecting Multiple Pipes With Multiple Children

I've been working on a function that works like a pipeline of a shell but receives a directory, go over it an search for every file to send it to a filter, something like this in bash "cat dir/* | cmd_1 | cmd_2 | ... | cmd_N", The only problem i have with the code is the redirection of the pipe descriptors.

Code:

int main(int argc, char* argv[]){
char** cmd;
int Number_cmd;
cmd = &(argv[2]); /*list of cmds*/
Number_cmd = argc-2; /*number of cmds*/
}

[code]....

The code is seems to work fine except when i run it with more than one command in example ("./filter DIR wc rev") in this case it returns

wc: standard input: Bad file descriptor
wc: -: Bad file descriptor
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