Having a trouble with opening FIFO in C

c file-io fifo mkfifo
ObjProg picture ObjProg · Dec 30, 2010 · Viewed 10.5k times · Source

I'm having a trouble in opening FIFOs in C.. first I created them using mkfifo() function with permission : 0777, and when I tried to open them, it succeeded in opening the first FIFO only, then the process will stuck in opening the second FIFO, and this is my code :

fd1 = open("FIFO1_PATH", O_WRONLY );
fd2 = open("FIFO2_PATH", O_WRONLY );

This will not be executed, but once I comment the second line, it executes ! Is there a limit for the number of opening FIFOs per process ? I don't know why is this happening.. I just spent 3 Hours trying to figure out what the problem is, but without any results :(

Answer

ObjProg picture ObjProg · Dec 30, 2010

I just got it right :)

I have to let the opening process wait until some other process opens the FIFO for reading (and it will be a blocked reading).. by doing sleep on the writing process I will ensure that the other process will opens for reading ..

Related questions

Unable to open FIFO for writing

'Server' program side: #define RESP_FIFO_NAME "response" /* Global Variables */ char *cmdfifo = CMD_FIFO_NAME; /* Name of command FIFO. */ char *respfifo = RESP_FIFO_NAME; /* Name of response FIFO. */ int main(int argc, char* argv[]) { int infd, outfd; /* FIFO file descriptors. */ ... // …

Read More
C read file line by line

I wrote this function to read a line from a file: const char *readLine(FILE *file) { if (file == NULL) { printf("Error: file pointer is null."); exit(1); } int maximumLineLength = 128; char *lineBuffer = (char *)malloc(sizeof(char) * maximumLineLength); if (lineBuffer == NULL) { printf("Error …

Read More
Read and write to binary files in C?

Does anyone have an example of code that can write to a binary file. And also code that can read a binary file and output to screen. Looking at examples I can write to a file ok But when I …

Read More