mkdir /tmp/phfiles

cd /usr/include
h2ph -d /tmp/phfiles -r -l .

cd /tmp/phfiles
grep sendmsg */*.ph
grep recvmsg */*.ph


##</code><code>##

$ cd /tmp/phfiles

$ grep sendmsg */*.ph
asm-generic/unistd.ph:eval 'sub __NR_sendmsg () {211;}' unless defined(&__NR_sendmsg);
asm/unistd_64.ph:    eval 'sub __NR_sendmsg () {46;}' unless defined(&__NR_sendmsg);
asm/unistd_x32.ph:    eval 'sub __NR_sendmsg () {( &__X32_SYSCALL_BIT + 518);}' unless defined(&__NR_sendmsg);
bits/syscall.ph:    eval 'sub SYS_sendmsg () { &__NR_sendmsg;}' unless defined(&SYS_sendmsg);
bits/syscall.ph:    eval 'sub SYS_sendmsg () { &__NR_sendmsg;}' unless defined(&SYS_sendmsg);

$ grep recvmsg */*.ph
asm-generic/unistd.ph:eval 'sub __NR_recvmsg () {212;}' unless defined(&__NR_recvmsg);
asm/unistd_64.ph:    eval 'sub __NR_recvmsg () {47;}' unless defined(&__NR_recvmsg);
asm/unistd_x32.ph:    eval 'sub __NR_recvmsg () {( &__X32_SYSCALL_BIT + 519);}' unless defined(&__NR_recvmsg);
bits/syscall.ph:    eval 'sub SYS_recvmsg () { &__NR_recvmsg;}' unless defined(&SYS_recvmsg);
bits/syscall.ph:    eval 'sub SYS_recvmsg () { &__NR_recvmsg;}' unless defined(&SYS_recvmsg);