Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: How to clear the content of a pipe (STDIN) after it is written to another program?
Top Forums Programming How to clear the content of a pipe (STDIN) after it is written to another program? Post 302195285 by vvaidyan on Wednesday 14th of May 2008 05:28:11 PM
Old 05-14-2008
Shamrock, sorry about not providing proper details previously.

Program A does have main() fn separately. Program A and B are completely two different programs, just that Program B is called through execl() in Program A.

Following are additional details on Program A.

PROGRAM A

Code:
int
main(int argc, char *argv[])
{
     // This program accepts several customized options through socket.
     // The option/module I am writing is called SearchFiles
     // This program does not exit until another option Terminate is called through client socket
     // Meaning, SearchFiles option can be called more than once
     // SearchFiles does operation nothing to do with pipes. it does a customized path translation. 
     // The data that it passes to StartPipe() method is only the socket and the path in a char array as below:

     sockinetbuf s;
     string socket_data;
     s >> socket_data;
     while(s)
     {
          s >> socket_data;

          if (socket_data == "SearchFiles")
          {
               char input_to_program_b[1000] = "blah blah blah";
               StartPipe(s, input_to_program_b);
          }
          else if (socket_data == "Terminate")
          {
               exit(0);
          }
     }
}

Function StartPipe() is as given in the first post.

Thanks,
Vivek
Last edited by vvaidyan; 05-14-2008 at 06:35 PM..
 

10 More Discussions You Might Find Interesting

1. Programming

How to write to stdin of another program (program A -> [stdin]program B)

Hi, Program A: uses pipe() I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using: * child -> dup2(fd, STDOUT_FILENO); -> execl("/path/PROGRAM B", "PROGRAM B", NULL); * parent -> char line; -> read(fd, line, 100); Question: ---------... (1 Reply)
Discussion started by: vvaidyan
1 Replies

2. Programming

C++ How to use pipe() & fork() with stdin and stdout to another program

Hi, Program A: uses pipe() I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using: * child -> dup2(fd, STDOUT_FILENO); -> execl("/path/PROGRAM B", "PROGRAM B", NULL); * parent -> char line; -> read(fd, line, 100); Question:... (2 Replies)
Discussion started by: vvaidyan
2 Replies

3. Shell Programming and Scripting

Perform action file name written to the pipe

Hello, I have a script that monitors files uploaded via ftp. After a successful upload, the file name is written to the pipe. There is another program that reads this pipe and allows automatically run any program or script ( say test.sh ) to process the newly uploaded file. cat test.sh... (2 Replies)
Discussion started by: fed.linuxgossip
2 Replies

4. UNIX for Dummies Questions & Answers

How to write to stdin of another program (program A -> [stdin]program B)

Hi, Program A: uses pipe() I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using: * child -> dup2(fd, STDOUT_FILENO); -> execl("/path/PROGRAM B", "PROGRAM B", NULL); * parent -> char line; -> read(fd, line, 100); Question: ---------... (3 Replies)
Discussion started by: vvaidyan
3 Replies

5. UNIX for Advanced & Expert Users

AIX 5.3 - There is no process to read data written to a pipe

I have the following code which works on AIX 4.3 but fails at times on AIX 5.3 with: cat: 0652-054 cannot write to output. There is no process to read data written to a pipe. validator="${validator_exe} ${validator_parms}" cmd_line="${CAT} ${data_file} | ${validator}... (6 Replies)
Discussion started by: vigsgb
6 Replies

6. AIX

Tape drive problem - no process to read data written to a pipe

Hi Everyone, The machine I'm working on is an AIX 5.3 LPAR running on a P650. oslevel -r shows 5300-08. I'm trying to take a backup to a SCSI tape drive, which has been working up until this point. I know of nothing that has changed recently to cause this problem. But when I try to take a... (0 Replies)
Discussion started by: need2bageek
0 Replies

7. UNIX for Dummies Questions & Answers

No process to read data written to a pipe on AIX

We use SAP application cluster on AIX. Communication between 2 of its instances is failing randomly with the following error: java.net.SocketException: There is no process to read data written to a pipe. The above error causes a cluster restart if an important communication fails. Can... (0 Replies)
Discussion started by: RoshniMehta
0 Replies

8. Programming

How to prevent a C++ program reading a file that is still being written to.?

Hi, Hopefully someone can help. We have a process that writes a file using Connect Direct to our local Solaris server and then our C++ program will pick up the file and process it. Unfortunately, because of the size of the file, the C++ program is processing the file before it has finished... (7 Replies)
Discussion started by: chris01010
7 Replies

9. Programming

Debugging a program written in two languages

Subject: Debugging a program written in two languages Platform: Linux (Kubuntu) I am trying to debug a C application with bindings to some simple functions written in Ada using the GNAT Programming Studio IDE (GPS). The main entry point is in C. The debugger is gdb. I managed to compile... (0 Replies)
Discussion started by: NiGHTS
0 Replies

10. Programming

Clear standard input buffer for C program in Linux

Hello friends! i am writing a code in which i take inputs (numbers) from user and count the total number of positive, negative and zeros entered. I need to clear my standard input buffer before scanf() command. My compiler is completely ignoring the fflush(stdin) command. its not even showing any... (1 Reply)
Discussion started by: Abhishek_kumar
1 Replies

LEARN ABOUT LINUX

__ppc_set_ppr_very_low

__PPC_SET_PPR_MED(3)					     LinuxProgrammer's Manual					      __PPC_SET_PPR_MED(3)

NAME

       __ppc_set_ppr_med, __ppc_set_ppr_very_low, __ppc_set_ppr_low, __ppc_set_ppr_med_low, __ppc_set_ppr_med_high - Set the Program Priority Reg-
       ister

SYNOPSIS

       #include <sys/platform/ppc.h>

       void __ppc_set_ppr_med(void);
       void __ppc_set_ppr_very_low(void);
       void __ppc_set_ppr_low(void);
       void __ppc_set_ppr_med_low(void);
       void __ppc_set_ppr_med_high(void);

DESCRIPTION

       These functions provide access to the Program Priority Register (PPR) on the Power architecture.

       The PPR is a 64-bit register that controls the program's priority.  By adjusting the PPR value the programmer may improve system throughput
       by  causing  system resources to be used more efficiently, especially in contention situations.	The available unprivileged states are cov-
       ered by the following functions:

       *  __ppc_set_ppr_med() sets the Program Priority Register value to medium (default).

       *  __ppc_set_ppr_very_low() sets the Program Priority Register value to very low.

       *  __ppc_set_ppr_low() sets the Program Priority Register value to low.

       *  __ppc_set_ppr_med_low() sets the Program Priority Register value to medium low.

       The privileged state medium high may also be set during certain time intervals by problem-state (unprivileged) programs, with the following
       function:

       *  __ppc_set_ppr_med_high() sets the Program Priority to medium high.

       If  the	program priority is medium high when the time interval expires or if an attempt is made to set the priority to medium high when it
       is not allowed, the priority is set to medium.

VERSIONS

       The functions __ppc_set_ppr_med(), __ppc_set_ppr_low() and __ppc_set_ppr_med_low() are provided by glibc since version 2.18.  The functions
       __ppc_set_ppr_very_low() and __ppc_set_ppr_med_high() first appeared in glibc in version 2.23.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +---------------------------+---------------+---------+
       |Interface		   | Attribute	   | Value   |
       +---------------------------+---------------+---------+
       |__ppc_set_ppr_med(),	   | Thread safety | MT-Safe |
       |__ppc_set_ppr_very_low(),  |		   |	     |
       |__ppc_set_ppr_low(),	   |		   |	     |
       |__ppc_set_ppr_med_low(),   |		   |	     |
       |__ppc_set_ppr_med_high()   |		   |	     |
       +---------------------------+---------------+---------+
CONFORMING TO

       These functions are nonstandard GNU extensions.

NOTES

       The  functions  __ppc_set_ppr_very_low()  and  __ppc_set_ppr_med_high()	will  be defined by <sys/platform/ppc.h> if _ARCH_PWR8 is defined.
       Availability of these functions can be tested using #ifdef _ARCH_PWR8.

SEE ALSO

       __ppc_yield(3)

       Power ISA, Book II - Section 3.1 (Program Priority Registers)

GNU C Library							    2017-09-15						      __PPC_SET_PPR_MED(3)
All times are GMT -4. The time now is 06:41 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy