/* getsndrcv.c: *  * Get SO_SNDBUF & SO_RCVBUF Options : */#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <assert.h>/* * This function reports the error and * exits back to the shell : */static voidbail(const char *on_what) {    if ( errno != 0 ) {        fputs(strerror(errno),stderr);        fputs(": ",stderr);    }    fputs(on_what,stderr);    fputc('\n',stderr);    exit(1);}intmain(int argc,char **argv) {    int z;    int s = -1;               /* Socket */    int sndbuf=0;   /* Send buffer size */    int rcvbuf=0;/* Receive buffer size */    socklen_t optlen;  /* Option length */    /*     * Create a TDP/IP socket to use :     */    s = socket(PF_INET,SOCK_STREAM,0);    if ( s == -1 )        bail("socket(2)");    /*     * Get socket option SO_SNDBUF :     */    optlen = sizeof sndbuf;    z = getsockopt(s,SOL_SOCKET,SO_SNDBUF,        &sndbuf,&optlen);    if ( z )        bail("getsockopt(s,SOL_SOCKET,"            "SO_SNDBUF)");    assert(optlen == sizeof sndbuf);    /*     * Get socket option SO_SNDBUF :     */    optlen = sizeof rcvbuf;    z = getsockopt(s,SOL_SOCKET,SO_RCVBUF,        &rcvbuf,&optlen);    if ( z )        bail("getsockopt(s,SOL_SOCKET,"            "SO_RCVBUF)");    assert(optlen == sizeof rcvbuf);    /*     * Report the buffer sizes :     */    printf("Socket s : %d\n",s);    printf(" Send buf: %d bytes\n",        sndbuf);    printf(" Recv buf: %d bytes\n",        rcvbuf);    close(s);    return 0;}