pipe passphrase to unlock key

[Face]

Hell all,

I am trying  to pipe my passphrase to unlock the key. my problem is
like this, when I use git
to sign a tag gnupg ask for the passphrase and i need to pipe the passphrase.

I try
echo "my long passphrase" | git tag -s 1.0.0.42 -m 'version 1.0.0.1'

however it did not work.

i also try writing a program to do the same thing

#include <stdio.h>
#include <unistd.h>
#include <string.h>
int my_pipe[2];

void ErrorAndExit(char* message) {
    fprintf(stderr, "%s\n", message);
    exit(1);
}
void WriteToPipe(char* s) {
    write(my_pipe[1], s, strlen(s));
}
int main(int argc, char* argv[]) {
    int pid;
    char* my_argv[]= {"/usr/bin/git",
              "tag",
              "-s",
              "1.0.0.2",
              "-m",
              "'version 1.0.0.2'",
                 0
                     };
    if (pipe(my_pipe) == -1) ErrorAndExit("pipe failed.");

    pid=fork();
    if (pid==-1) ErrorAndExit("fork failed.");
    if (pid==0) {
        /* son process */
        close(0);
        dup(my_pipe[0]);
        close(my_pipe[0]);
        close(my_pipe[1]);
        execv(my_argv[0], my_argv);
        ErrorAndExit("Program not found.");
    }
    /* father process */
    WriteToPipe("My Really Really Really Really Long passphrase \n");
    WriteToPipe("\n");

    return 0;
}

The problem with this code it keep writing to the pipe and would not exit.


is there is any workaround for my problem ?


Any help would be much appreciated.

Sincerely,
falazemi

note: using pinentry-curses