How to clear the content of a pipe (STDIN) after it is written to another program?
PROGRAM A <-> PROGRAM B
PROGRAM A sends data as STDIN ro PROGRAM B and when PROGRAM B is executed from PROGRAM A, it sends output back to PROGRAM A. This is implemented using 2 pipes (fd1 & fd2).
The above process happens in a loop and during the second run, the previous data that had been written as STDIN to PROGRAM B, it does not get cleared. The input data on STDIN to PROGRAM B just gets overwritten and the extra characters just stay there.
How to clear the STDIN to PROGRAM B? Existing code as follows:
PROGRAM A
The PROGRAM A code shown above is in a while condition loop, which can run more than once not exiting the program.
PROGRAM B
Just to check if correct data is got as input to PROGRAM B, we are just reading STDIN and echoing back on STDOUT. Previous data (without PROGRAM A exiting) stays on STDIN of PROGRAM B, which needs to be cleared before writing new input data to STDIN of 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)
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)
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)
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)
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Hi,
Hopefully someone can help.
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