Search DaniWeb - pipe

Pipe() System Call 14 Years Ago by sciprog1 Hello Members, I am trying to understand the pipe() system call. I found this program online…MSGSIZE]; int p[2], j; /* open pipe */ if(pipe(p) == -1) { perror("pipe call error"); exit(1); } /* …, MSGSIZE); write(p[1], msg3, MSGSIZE); /* read pipe */ for(j=0; j<3; j++) { … Re: Pipe() System Call 14 Years Ago by Rajenar HI... As per my operating system knowledge, PIPE is a file type which resides in RAM. Pipe has two ends one is read… and another is write. when u call system call pipe u ll have two typea of disriptor in user file… Re: Pipe() System Call 14 Years Ago by Ancient Dragon read [URL="http://www.opengroup.org/onlinepubs/009695399/functions/pipe.html"]this thread [/URL]and its example program. Pipe problems in C 13 Years Ago by BobTheLob … close(p[1]); exit(EXIT_SUCCESS); default://parent is active. Read pipe messages (2) close(p[1]); read(p[0], inbuf, …close(p[1]); exit(EXIT_SUCCESS); default://parent is active. Read pipe messages (2) close(p[1]); read(p[0], inbuf, … Re: Pipe problems in C 13 Years Ago by nezachem …Each of the 3 processes create a unique, distinctly separate pipe, and they are not related to each other. On the…hand, what happens in the correct sequence (first create a pipe, then fork, as in L5Sqr example): fork clones the …userspace, yet the pipe, which is a kernel object, is not cloned. That is… Pipe() and Execve() Problem 16 Years Ago by otterfreak …to call mpg function*/ /* Create a pipe */ err=pipe(toServer); /*For reading*/ err=pipe(fromServer); /*For writing*/ if(err==-1)… if(err==-1) { printf("Error on read from pipe: %d\n", errno); exit(2); } sscanf(… if(err==-1) { printf("Error on write to pipe: %d\n", errno); exit(3); } sprintf(… Re: Pipe() and Execve() Problem 16 Years Ago by otterfreak …quot;,input); /* Create a pipe */ err=pipe(&toServer[1]); /*For reading*/ err=pipe(&fromServer[0]); /*For writing…*/ if(err==-1) { printf("Error on pipe creation: %d\n",errno); exit(1); } pid…if(err==-1) { printf("Error on read from pipe: %d\n", errno); exit(2); } sscanf(… Re: Pipe() and Execve() Problem 16 Years Ago by nucleon … the base pointer of the 2-element int array to pipe. Also, try cleaning up your error handling, something like this…(msg); exit(1); } ... if (pipe(toServer) == -1) die("pipe to"); if (pipe(fromServer) == -1) die("pipe from"); if ((pid = fork… Re: Pipe problems in C 13 Years Ago by L7Sqr …think your shared use of the pipe in each child is causing you…pid2 = 0; int pipes1[2] = {0}, pipes2[2] = {0}; pipe(pipes1); /* for child 1 */ pid1 = fork (); if (pid1 == 0)… wrote\n"); exit (0); } /* Parent continues here */ pipe(pipes2); pid2 = fork (); if (pid2 == 0) { /* … Re: Pipe problems in C 13 Years Ago by BobTheLob …! My mind is still trying to fully understand fork and pipe commands, but that code makes a lot of sense (my… Re: Pipe problems in C 13 Years Ago by BobTheLob … supposed to wait until something has been written to the pipe, and won't continue till something is in there? Re: Pipe problems in C 13 Years Ago by L7Sqr … the first child or you can not read from the pipe in the parent? (The two situations are wildly different… Re: Pipe in C 12 Years Ago by Lucaci Andrew well by fork() you'll create a child process. the pipe works like this: on one end you write something and… like this, I'll write it in pseudocode: int a2b pipe(a2b) if fork()==0 then write(a2b[1], information, size… solve the required problem, and write the answer to the pipe, then exit the child. Then, after the parent waits … pipe reading/writing 16 Years Ago by jesseb07 … usually) and somehow it automatically goes to the pipe's stdin and works, I want to automate the…lt;< endl; //writes each line gotten from the pipe temp = text; //converts to string to I can use…the stream } } pclose(file); cout << "Closed pipe"; cout << endl; return 0; } [/CODE] … Pipe Email to PHP 14 Years Ago by nquinlan I am trying to pipe an email to PHP. I currently have set…is a permanent error. The following address(es) failed: pipe to |/home/username/public_html/mailscripttest.php generated by [email]…The following text was generated during the delivery attempt: ------ pipe to |/home/username/public_html/mailscripttest.php generated by [email]… Pipe in C 12 Years Ago by jeevsmyd … find the factors of a number and pass it use pipe function from child to main process. I googled up the… syntax of pipe and I find it difficult to understand the idea. You… file pointer and all to pass an array back using pipe? Isn't the mechanism as simple as passing arguments to… Pipe alternative 12 Years Ago by liran …;. I need to do this: yes | command but without a pipe, there is a reason for this, because for the specific… use, pipe before the command is not allowed, that's not the… use which will output do the same thing without the pipe ? Maybe something like this: command < yes (which will not… Re: Pipe alternative 12 Years Ago by L7Sqr The problem, I believe, is not how to limit the output of `yes`; you've clearly demonstrated how to do that. I think the more difficult problem is doing that without using a pipe (thus preventing a 'broken pipe' from terminating `yes`). Re: pipe reading/writing 16 Years Ago by jesseb07 thanks for the reply. While I was unaware that an fflush() or fseek() is required, it still doesn't solve the segmentation fault. It faults upon opening the pipe, all else held constant, adding a "+" causes a fault. I'm going away for the weekend so I won't be able to respond til late sunday. ~J Pipe as field terminator in TSQL 14 Years Ago by Tommymac501 … a SQL file that needs to be BCP exported to pipe delimited because of limitations on the recieving end. I have…] + '.txt" -t^|, -c -T' All of them produce the pipe as the delimiter, but, the pipes are also followed by… pipe and fork? 13 Years Ago by wildplace hey, today my teacher told us to use pipe and fork to write a program without teaching us anyway... if any would recommend some good tutorials would be great~!! and what does fork a child mean really mean(example would be great), and how write to a pipe? everything is done in linux with g++. thanks! Re: pipe and fork? 13 Years Ago by zeroliken … would be great[/QUOTE] [URL="http://lmgtfy.com/?q=pipe+and+fork+tutorials+C%2B%2B"]Did you try… this?[/URL] [QUOTE]today my teacher told us to use pipe and fork to write a program without teaching us anyway… Re: Pipe alternative 12 Years Ago by Nutster You could try: #/bin/sh yes > /tmp/tmpout command < /tmp/tmpout rm /tmp/tmpout You could even put it in a shell script, but then you could go back to using the pipe then as well. Pipe implementation in C/C++ 11 Years Ago by hemanshurpatel … is the application/utility which takes input from ls via pipe. I want to implement the same in C. I Did… following things 1. Created PIPES using pipe command 2. close local input via close(0) 3. use… Re: Pipe implementation in C/C++ 11 Years Ago by Tumlee When you pipe two programs together via the shell, it actually just pumps … on the right. There is no real need for calling `pipe()` inside your program in this case. For example, if I… Re: Pipe as field terminator in TSQL 14 Years Ago by Tommymac501 Solved it.. I didn't notice the Pipe was followed by a comma in my code.. Re: Pipe Output 13 Years Ago by BitBlt … Custom Delimiter text box appears, type in the "|" (pipe) character. Note: make sure the maximum number of characters is…. Once the query is complete (you should see a nice pipe-delimited result set) then right-click anywhere on the results… Re: pipe and fork? 13 Years Ago by scarcella Yeah i am wondering the same thing, what is pipe and fork? Re: pipe and fork? 13 Years Ago by vimalseo This is actually used in process handling programs related to operating systems. A fork is actually a system call to create a new process which is an identical process to the parent process but having different process ID where as pipe is a system call that facilitates inter-process communication. Pipe broken at 2GB when tarring to a samba mount 17 Years Ago by bdb4269 … the following error. [CODE]backupjob.bash: line 79: 25891 Broken pipe[/CODE] This only happens if I run the tar command…