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2
votes
1answer
278 views

Why doesnt ctrl+d work with this?

I wanted a simple way to process text in my clipboard without having to create a file. I tried using the following line: awk '{print $1}' <(cat) but I couldn't send cat the EOF character using ...
2
votes
2answers
304 views

AIX open() : file descriptor is zero (!?)

A daemon process, on detecting the presence of a text file in a particular directory then launches an executable file which opens the aforementioned text file in order to read and then transmit its ...
2
votes
1answer
258 views

open() console for default file descriptors

I'm reading a shell program implementation in C ( the xv6 shell from MIT's 6.828 Operating System Engineering course ). The main() function for this shell starts with the following code: //Assumes ...
2
votes
1answer
66 views

How is the inherited file descritor vulnerability dealt with in Unices?

Ulrich Drepper describes a vulnerability in programs that have open file descriptors then they fork() and execve() without lots of very careful locking in place. He also talks about new kernel ...
2
votes
1answer
138 views

Max Open Files, clarification needed

On my machine, ulimit -n returns 2560 Given that -n returns The maximum number of open file descriptors. Does it mean that system won't allow more then 2560 open files to be out there at any ...
2
votes
1answer
37 views

Is there a system call to bind a file descriptor directly into another?

A read() & write() loop would probably be as good as what I'm looking for, but nevertheless is anything like that around or is it impossible because of an obstacle I didn't envisage ? I'm curious
2
votes
0answers
13 views

Is it safe to create a regression test that relies on running out of file descriptor limit?

I'm writing a regression test for my modification of Nmap and I'm wondering if it's a good idea to create a test that would basically perform a large-scale connect() scan on 127.0.0.1/8, which would ...
1
vote
3answers
887 views

How to check which process is using a given file descriptor?

Somewhere in the middle of my application, the framework I'm using (ROOT) gives me the following error: *** Break *** write on a pipe with no one to read it SysError in ...
1
vote
2answers
48 views

What fd's are used when doing diff <(cat old) <(cat new)?

If I do: diff <(cat old) <(cat new) Hoe does that work internally for the diff program? And how I do the same trick with a bash script?
1
vote
3answers
75 views

Print a message from the left-hand side of a pipe

I want to use a variable from the main shell in a sub shell. I did: export mysql_root_password="test" ( echo $mysql_root_password ) | dialog --gauge "Working hard..." 6 50 But it does not ...
1
vote
0answers
159 views

Which socket is gnome-shell reading from continuously?

strace shows that the GNOME shell is continuously trying to read from a socket, which is often not available (or doesn't contain any data to read from): strace -p gnome-shell-pid -e trace=recvfrom ...
0
votes
2answers
198 views

Why doesn't Bash accept `&>&3`, i.e. redirecting stdout and stderr to file descriptor 3?

Given the preamble, foobar function and invocations of it: exec 3>/dev/null function foobar { echo foo; echo bar >&2; } foobar >/dev/null foobar 2>/dev/null foobar ...
0
votes
2answers
133 views

How to reset the file descriptor

I was trying to use file descriptor for printing the lines in the file #!/usr/bin/ksh exec 3<&0 exec 0< file.txt while read LINE do echo “$LINE” done and I am done with my code ,it ...
0
votes
1answer
348 views

Understand Fd`s and nodejs

I'm having a bit of a confused time understanding what a file descriptor is and if I even need one! I am trying to spawn a process in nodejs and have its out put be written directly to an out put ...
0
votes
0answers
4 views

Working of dup3 [migrated]

Hi while reading dup3 system call, i got that it will change only O_CLOEXEC flag of duplicated file desriptor. But when i have written below program for all the 3 outputs it printed the flag is either ...
0
votes
0answers
230 views

Embedded device GadgetFS connects to Linux machine and receives one USB setup request more than with a windows machine connected

I am using this GadgetFS implementation http://www.linux-usb.org/gadget/usb.c to have my embedded device connect to a Host. What's weird is, when I connect it to a Windows machine everything works ...