Sponsored Content
Top Forums UNIX for Dummies Questions & Answers int open(const char *pathname, int flags, mode_t mode) doubt... Post 302145827 by jim mcnamara on Thursday 15th of November 2007 10:33:45 AM
Old 11-15-2007
Where you have O_CREAT:

from the open man page:
Quote:
Exactly one of the O_RDONLY, O_WRONLY, or O_RDWR flags must be used in
composing the value of oflag. If none or more than one is used, the
behavior is undefined.
You are seeing undefined behavior.
 

10 More Discussions You Might Find Interesting

1. Programming

difference between int ** func() and int *& func()

What is the difference between int** func() and int*& func(). Can you please explain it with suitable example. Thanks, Devesh. (1 Reply)
Discussion started by: devesh
1 Replies

2. Red Hat

cast from const void* to unsigned int loses precision

Hello everey one, here i am attempting to compile a c++ project .it's throughing the following errors. my machine details are as follows: Linux chmclozr0119 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:19 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux errors: ===== Generating... (0 Replies)
Discussion started by: mannam srinivas
0 Replies

3. Programming

How to read flags from mode_t type?

Hello, After, I stat() a file, how can I read the various permissions flags from the st_mode variable which is of type mode_t? I would like to do something like: struct stat *perms; int res = stat(filename, perms); if(perms->st.mode == S_IROTH) do something; but I know that is the wrong... (2 Replies)
Discussion started by: pallak7
2 Replies

4. Programming

concat const char * with char *

hello everybody! i have aproblem! i dont know how to concatenate const char* with char const char *buffer; char *b; sprintf(b,"result.txt"); strcat(buffer,b); thanx in advance (4 Replies)
Discussion started by: nicos
4 Replies

5. Programming

conversion to 'char' from 'int' warning

Hi, I wrote a simple code in C++ converting from UpperToLower case characters. However, my compiler gives me a warning: "warning: conversion to 'char' from 'int' may alter its value". Any tips? I would like to stress, I don't want to load my string into char array. int ToLower(string... (4 Replies)
Discussion started by: kajolo
4 Replies

6. Programming

Handle int listen(int sockfd, int backlog) in TCP

Hi, from the manual listen(2): listen for connections on socket - Linux man page It has a parameter called backlog and it limits the maximum length of queue of pending list. If I set backlog to 128, is it means no more than 128 packets can be handled by server? If I have three... (3 Replies)
Discussion started by: sehang
3 Replies

7. Programming

C++ program is crashing on re-assigning const static member variable using an int pointer

Hi, Can any one tell me why my following program is crashing? #include <iostream> using namespace std; class CA { public: const static int i; }; const int CA::i = 10; int main() { int* pi = const_cast<int*>(&CA::i); *pi = 9; cout << CA::i << endl; } (6 Replies)
Discussion started by: royalibrahim
6 Replies

8. Programming

error: invalid conversion from ‘const char*’ to ‘char*’

Compiling xpp (The X Printing Panel) on SL6 (RHEL6 essentially): xpp.cxx: In constructor ‘printFiles::printFiles(int, char**, int&)’: xpp.cxx:200: error: invalid conversion from ‘const char*’ to ‘char*’ The same error with all c++ constructors - gcc 4.4.4. If anyone can throw any light on... (8 Replies)
Discussion started by: GSO
8 Replies

9. Programming

Help with understanding ( int, char, long, short, signed, unsigned etc.... )

My question is simple: When should I use a long, int, char, unsigned/signed variables?? When I declare a variable "unsigned;" what did I do it??? Why would I delcare an integer "long" or "short" ( unsigned or signed)?? Any examples of when things like "unsigned", "long", "short" etc...... (6 Replies)
Discussion started by: cpp_beginner
6 Replies

10. Programming

Small query regarding function "char * strerror(int errnum)"

As this function returns the address of the string corressponding to the errno value provided to it. Can someone please let me know where, in the memory, it could be (on freeBSD). The MAN page tells under the BUG section that "For unknown error numbers, the strerror() function will return its... (5 Replies)
Discussion started by: Praveen_218
5 Replies
MKFIFO(3)						     Linux Programmer's Manual							 MKFIFO(3)

NAME
mkfifo - make a FIFO special file (a named pipe) SYNOPSIS
#include <sys/types.h> #include <sys/stat.h> int mkfifo(const char *pathname, mode_t mode); DESCRIPTION
mkfifo() makes a FIFO special file with name pathname. mode specifies the FIFO's permissions. It is modified by the process's umask in the usual way: the permissions of the created file are (mode & ~umask). A FIFO special file is similar to a pipe, except that it is created in a different way. Instead of being an anonymous communications chan- nel, a FIFO special file is entered into the file system by calling mkfifo(). Once you have created a FIFO special file in this way, any process can open it for reading or writing, in the same way as an ordinary file. However, it has to be open at both ends simultaneously before you can proceed to do any input or output operations on it. Opening a FIFO for reading normally blocks until some other process opens the same FIFO for writing, and vice versa. See fifo(7) for nonblocking handling of FIFO special files. RETURN VALUE
On success mkfifo() returns 0. In the case of an error, -1 is returned (in which case, errno is set appropriately). ERRORS
EACCES One of the directories in pathname did not allow search (execute) permission. EEXIST pathname already exists. This includes the case where pathname is a symbolic link, dangling or not. ENAMETOOLONG Either the total length of pathname is greater than PATH_MAX, or an individual filename component has a length greater than NAME_MAX. In the GNU system, there is no imposed limit on overall filename length, but some file systems may place limits on the length of a component. ENOENT A directory component in pathname does not exist or is a dangling symbolic link. ENOSPC The directory or file system has no room for the new file. ENOTDIR A component used as a directory in pathname is not, in fact, a directory. EROFS pathname refers to a read-only file system. CONFORMING TO
POSIX.1-2001. SEE ALSO
mkfifo(1), close(2), open(2), read(2), stat(2), umask(2), write(2), mkfifoat(3), fifo(7) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. GNU
2008-06-12 MKFIFO(3)
All times are GMT -4. The time now is 05:26 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy