Question

I am trying to make a c++ program that sends an email using the mail command, using a string as the body. To set the string of the message, I am trying to pipe a message in.

For example, I am trying the following, which should send an email to [e-mail] with a message saying “test”, but no message is sent. Any ideas?:

fp = fopen("mail [e-mail]", "w+");
dup2(fileno(fp), 1);
fclose(fp);
printf("test\n");

Answer 1

Your first argument to fopen is not a file, and fopen is for opening files.

Try using popen to open a pipe connected to a subprocess instead:

fp = popen("mail [e-mail]", "w")