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I am trying to read some text from a file and write it to another using open() , read() and write() . This is my open() for the file-to-write-to (I want to create a new file and write into it): fOut = open ("test-1", O_RDWR | O_CREAT | O_SYNC); This is setting file-permissions to something I don't understand at all. This is the output of ls -l : ---------T 1 chaitanya chaitanya 0 2010-02-11 09:38 test-1 Even the read permission is locked. I tried searching for this, but could not find ANYTHING. Strangely, write() still successfully writes data to the file. Also, if I do a 'chmod 777 test-1', things start working properly again. Could someone please let me know where I am going wrong in my open call? Thanks! For your reference, I have pasted the complete program below: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> int main () { char buffer[512], ch; int fIn, fOut, i; ssize_t bytes; FILE *fp = NULL; //open a file fIn = open ("test", O_RDONLY); if (fIn == -1) { printf("\nfailed to open file."); return 1; } //read from file bytes = read (fIn, buffer, sizeof(buffer)); //and close it close (fIn); printf("\nSuccessfully read %d bytes.\n", bytes); //Create a new file fOut = open ("test-1", O_RDWR | O_CREAT | O_SYNC); printf("\nThese are the permissions for test-1\n"); fflush(stdout); system("ls -l test-1"); //write to it and close it. write (fOut, buffer, bytes); close (fOut); //write is somehow locking even the read permission to the file. Change it. system("chmod 777 test-1"); fp = fopen ("test-1", "r"); if (fp == NULL) { printf("\nCan't open test-1"); return 1; } whi

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