473,796 Members | 2,425 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Help with open, dup and dup2

What sequence of calls to open, dup and/or dup2 do you perform in your
program in order to achieve the following effects?

$prog1>file 2>&1

and

$prog2 2>&1 > file

I understand which each line does, but I dont understand how to use dup
and dup2 to acheive this. I don't necessarily need code just an
understanding of how do accomplish this.

Mar 16 '06 #1
2 2507
se****@gmail.co m writes:
What sequence of calls to open, dup and/or dup2 do you perform in your
program in order to achieve the following effects?

[snip]

None. open, dup, and dup2 are not defined in standard C.
Try comp.unix.progr ammer.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
Mar 16 '06 #2
se****@gmail.co m wrote:
What sequence of calls to open, dup and/or dup2 do you perform in your
program in order to achieve the following effects?

$prog1>file 2>&1

and

$prog2 2>&1 > file

I understand which each line does, but I dont understand how to use dup
and dup2 to acheive this. I don't necessarily need code just an
understanding of how do accomplish this.

Pop along to comp.unix.progr ammer and post again.

--
Ian Collins.
Mar 16 '06 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

2
3560
by: fabien | last post by:
Hi, I am writing a POV-RAY editor with Python using either QT or GTK as GUI 'wrapper'. ( I am still trying both ) * * * * PYGTK * * * * I have downloaded PygtkScintilla-1.99.5. There is a lexPOV.cxx file in the package, but I can not find any POV keywords in any file ( there are about 150 POV keywords). Did i miss it, and if not, how do I create one and include it for the library building ?
3
2710
by: Abhas | last post by:
> > Hi, this is Abhas, > > I had made a video library program in C++, but was facing a problem. > > After entering 12 movies, i cannot enter any more movies. > > Something gibberish comes instead. > > Can somebody please tell whats wrong?? > > This is the code : : #include<fstream.h> #include<conio.h>
2
3307
by: chanchito_cojones | last post by:
hi there, I am needing some help with a database I am putting together. The database works off of a main Form, which then has buttons on it that will open up other forms. The problem I am having is that if I am updating any information on the current record, and then open one of the other forms, the new form will not show the updated information. I realize that a simple macro solves this problem by basically closing the first form,...
3
17395
by: PC | last post by:
Is it possible to create pipe()s (stdin/stdout) for a child process and forking a shell with execl() and controlling the shell's stdin/stdout from the parent with select()? Heres a little snippet of code. it doesnt actually work.. but it is how I envisioned it:: if((n=accept(s,(struct sockaddr *)&remote,&sz))==-1) {printf("accept\n"); exit(0);} close(0); close(1); close(2); pipe(&i);
1
1799
by: ipellew | last post by:
Hi; I open another browser window for help. It stays open untill I press help on my main web window again to close this help. If I "reload" the main window with this help page open in the main window the browser complains of a "script stop running". How do I deal with an open "help" web window on this reload?
4
6467
by: DyslexicAnaboko | last post by:
Hello, I have a module that is part of larger project that is giving me trouble, so I setup an example. Brief ===== I simply want to open a text file and make the contents avaliable through stdin that way a bourne shell script I wrote will execute
1
1595
by: KiranJyothi | last post by:
Hello All, In whotofile.c, we can see that we are redirecting the output of who to a file. In pipe.c, we see that we are redirecting the o/p of first command as the input to the next command. I want to write a program without using dup or dup2 to redirect the output of who as the input of sort. Can anyone please help me with this?
3
3307
by: wrenashe | last post by:
I am on windows 2003, basically my codes want to do such a thing: 1. fopen a file A. 2. dup2(A, stdout); 3. dup2(A, stderr); 4. fclose(A); 5. rename(A), and move it to somewhere else. 6, fopen(A); 7. dup2(A, stdout); 8. dup2(A, stderr);
6
2883
by: priyajohal | last post by:
#include<fstream.h> #include<process.h> #include<stdlib.h> #include<conio.h> #include<string.h> #include<dos.h> #include<ctype.h> #include<stdio.h> void setup() void help();
0
9528
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
0
10455
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
0
10228
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
0
9052
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
0
6788
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
5441
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
0
5573
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
2
3731
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.
3
2925
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.