sudo strace -s 700000 -e read,write,execve,kill,close,open,send,recv,stat -f -- apt-get -q -y install mysql-client-core-5.6=5.6.19-0ubuntu0.14.04.1
....
Process 18371 attached
[pid 18359] close(25)                   = 0
[pid 18359] close(26)                   = 0
[pid 18371] execve("/usr/lib/apt/methods/http", ["/usr/lib/apt/methods/http"], [/* 16 vars */]) = 0
....
[pid 18371] write(1, "100 Capabilities\nVersion: 1.2\nPipeline: true\nSend-Config: true\n\n", 64) = 64
[pid 18359] read(24, "100 Capabilities\nVersion: 1.2\nPipeline: true\nSend-Config: true\n\n", 64000) = 64
[pid 18359] close(24)                   = 0
[pid 18359] close(27)                   = 0
[pid 18359] kill(18371, SIGINT)         = 0
[pid 18371] --- SIGINT {si_signo=SIGINT, si_code=SI_USER, si_pid=18359, si_uid=0} ---