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A co-worker of mine is using some of Scott Klements programs to learn to use
Sockets APIs.
She is working on a program that is based on CLIENTEX1. I beleive she
changed it to use procedures, and added a display screen.
On screen she has a service field and a host name as well as a command line
and a response field. When she enters 25 in the service and Bypass (our
server name)in the host, she receives a response back.
She then enters 'HELO' in the command field and presses enter. The program
goes into a loop that executes
rc = recv(sock: %addr(ch): 1: 0)
The first 3 times it receives back non-displayable characters and the 4th
time it hangs while on recv
She is translating from EBCIC to ASCII just before calling recv, and back
from ASCII back to EBCDIC just before displaying the green screen.
She also was trying to key commands to talk to a couple devices we have on
the network that required an escape character, and a Carriage Return. When
she typed those commands, nothing happened.
Following is the source excerpt, we are wondering if Scott or anyone else
familiar with the api would mind taking a look to see a problem jumps out at
them.
Thank you much in advance for any help you can provide.
D Open_Session pr
D End_Session pr
D DsplyLine pr
D Talk pr
D getservbyname PR * ExtProc('getservbyname')
D service_name * value options(*string)
D protocol_name * value options(*string)
D p_servent S *
D servent DS based(p_servent)
D s_name *
D s_aliases *
D s_port 10I 0
D s_proto *
D inet_addr PR 10U 0 ExtProc('inet_addr')
D address_str * value options(*string)
D INADDR_NONE C CONST(4294967295)
D inet_ntoa PR * ExtProc('inet_ntoa')
D internet_addr 10U 0 value
D p_hostent S *
D hostent DS Based(p_hostent)
D h_name *
D h_aliases *
D h_addrtype 10I 0
D h_length 10I 0
D h_addr_list *
D p_h_addr S * Based(h_addr_list)
D h_addr S 10U 0 Based(p_h_addr)
D gethostbyname PR * extproc('gethostbyname')
D host_name * value options(*string)
D socket PR 10I 0 ExtProc('socket')
D addr_family 10I 0 value
D type 10I 0 value
D protocol 10I 0 value
D SOCK_SEQPACKET C CONST(5)
D AF_INET C CONST(2)
D SOCK_STREAM C CONST(1)
D IPPROTO_IP C CONST(0)
D connect PR 10I 0 ExtProc('connect')
D sock_desc 10I 0 value
D dest_addr * value
D addr_len 10I 0 value
D p_sockaddr S *
D sockaddr DS based(p_sockaddr)
D sa_family 5I 0
D sa_data 14A
D sockaddr_in DS based(p_sockaddr)
D sin_family 5I 0
D sin_port 5U 0
D sin_addr 10U 0
D sin_zero 8A
D send PR 10I 0 ExtProc('send')
D sock_desc 10I 0 value
D buffer * value
D buffer_len 10I 0 value
D flags 10I 0 value
D recv PR 10I 0 ExtProc('recv')
D sock_desc 10I 0 value
D buffer * value
D buffer_len 10I 0 value
D flags 10I 0 value
D close PR 10I 0 ExtProc('close')
D sock_desc 10I 0 value
D translate PR ExtPgm('QDCXLATE')
D length 5P 0 const
D data 32766A options(*varsize)
D table 10A const
D msg S 50A
D sock S 10I 0
D port S 5U 0
D addrlen S 10I 0
D ch S 1A
D host s 32A
D file s 32A
D IP s 10U 0
D p_Connto S *
D RC S 10I 0
D Request S 60A
D ReqLen S 10I 0
D RecBuf S 50A
D RecLen S 10I 0
C*************************************************
C* The user will supply a hostname and file
C* name as parameters to our program...
C*************************************************
C read uncname
C eval zzdnam = cndnam
C dou *in12 = *on
C eval zzrcv = *blanks
C eval zzcommand = *blanks
C eval zzrcv = *blanks
C exfmt socket1R
C select
C when *in02 = *on
C callp Open_Session
C callp Talk
C when *in04 = *on
C callp End_Session
C other
C callp Talk
C endsl
c exfmt socket1r
C eval zzrcv = *blanks
C enddo
C callp End_Session
*******************************************************************
* Procedure to Connect to socket
* Input parms: none
* Return value: none
*******************************************************************
P Open_Session b
D Open_Session pi
C*************************************************
C* what port to contact
C*************************************************
c eval port = %dec(zzsvc:5:0)
C*************************************************
C* Get the 32-bit network IP address for the host
C* that was supplied by the user:
C*************************************************
c eval IP = inet_addr(%trim(zzhost))
c if IP = INADDR_NONE
c eval p_hostent = gethostbyname(%trim(zzhost))
c if p_hostent = *NULL
c eval zzrcv = 'Unable to find that host!'
c exfmt socket1r
c return
c endif
c eval IP = h_addr
c endif
C*************************************************
C* Create a socket
C*************************************************
c eval sock = socket(AF_INET: SOCK_STREAM:
c IPPROTO_IP)
c if sock < 0
c eval zzrcv = 'Error calling socket()!'
c exfmt socket1r
c return
c endif
C*************************************************
C* Create a socket address structure that
C* describes the host & port we wanted to
C* connect to
C*************************************************
c eval addrlen = %size(sockaddr)
c alloc addrlen p_connto
c eval p_sockaddr = p_connto
c eval sin_family = AF_INET
c eval sin_addr = IP
c eval sin_port = port
c eval sin_zero = *ALLx'00'
C*************************************************
C* Connect to the requested host
C*************************************************
C if connect(sock: p_connto: addrlen) < 0
c eval zzrcv= 'unable to connect to server!'
c exfmt socket1r
c callp close(sock)
c return
c endif
P Open_Session e
*******************************************************************
* Procedure to Send and Receive requests
* Input parms: none
* Return value: none
*******************************************************************
P Talk b
D Talk pi
C*************************************************
C* Format a request for the file that we'd like
C* the http server to send us:
C*************************************************
c eval request = %trim(zzcommand)
c + x'0D' + x'0A'
c*** ' HTTP/1.1' + x'0D25' + x'0D25'
c eval reqlen = %len(%trim(request))
c callp Translate(reqlen: request: 'QTCPASC')
C eval request = %trim(request)
C*************************************************
c* Send the request to the http server
C*************************************************
c eval rc = send(sock: %addr(request): reqlen:0)
c if rc < reqlen
c eval zzrcv= 'Unable to send entire request!'
c exfmt socket1r
c callp close(sock)
c return
c endif
C*************************************************
C* Get back the server's response
C*************************************************
C eval cnt = 0
c dou rc<1
C callp DsplyLine
c enddo
P Talk e
*******************************************************************
* Procedure to Receive text from server
* Input parms: none
* Return value: none
*******************************************************************
P DsplyLine b
D DsplyLine pi
C*===============================================================
C* This subroutine receives one line of text from a server and
C* displays it on the screen using the DSPLY op-code
C*===============================================================
C* Receive one line of text from the HTTP server.
C* note that "lines of text" vary in length,
C* but always end with the ASCII values for CR
C* and LF. CR = x'0D' and LF = x'0A'
C*
C* The easiest way for us to work with this data
C* is to receive it one byte at a time until we
C* get the LF character. Each time we receive
C* a byte, we add it to our receive buffer.
C*************************************************
c eval reclen = 0
c eval recbuf = *blanks
c dou reclen = 50 or ch = x'0A'
c if end =1
C leave
C endif
c eval rc = recv(sock: %addr(ch): 1: 0)
c if rc < 1
c leave
c endif
c if ch<>x'0D' and ch<>x'0A'
c eval reclen = reclen + 1
c eval %subst(recbuf:reclen:1) = ch
c endif
c enddo
C*************************************************
C* translate the line of text into EBCDIC
C* (to make it readable) and display it
C*************************************************
c if reclen > 0
c callp Translate(reclen: recbuf: 'QTCPEBC')
C eval zzrcv = %trim(zzrcv) + recbuf
c endif
P DsplyLine e
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