Programming :: Return Error From Ioctl Command?
Jul 21, 2010
I'm creating a usb device driver that needs to be able to read from two different endpoints. I couldn't see any way of having two read functions in the driver, so I got round this by reading from one of the endpoints with read, and the other with ioctl.However this hasn't worked, the ioctl call from c returns -1. I added a printk command in the driver in the ioctl function, however looking at kern.log I can see that this function is never being called. Does anyone have any ideas as to what the problem called be, or a better method of being able to read from two different endpoints?
View 2 Replies
ADVERTISEMENT
Jul 4, 2011
I want to modify ioctl TIOCMWAIT to return the same thing that ioctl TIOCMGET returns. Currently wait returns an int of zero or -1 when a change in status occurs. Why not make it return the new status?
This will make the operation faster by not requiring another call to ioctl.The extra call requires 2 to 16 uSeconds to complete on my x64 laptop. How would I make this proposal to the kernal people?
View 1 Replies
View Related
Jul 1, 2010
I use ioctl to get the console window size (the SSH window). I use the following code:
struct winsize ws;
int returnValue = ioctl(pCommandStructure->terminal, TIOCGWINSZ, &ws);
int numberOfColumnsOfTerminalWindow = ws.ws_col;
When I debug on linux pc, it gives me the correct window width. But after I try it on router (this is my enventual place where my code shall run), ioctl always give me 0 width, that is, numberOfColumnsOfTerminalWindow == 0. but the returnValue is 0 which means that the function call succeeds.
View 2 Replies
View Related
Jul 1, 2010
I use ioctl to get the cosole window size (the SSH window).
I use the following code:
When I debug on linux pc, it gives me the correct window width. But after I try it on router (this is my enventual place where my code shall run), ioctl always give me 0 width, that is, numberOfColumnsOfTerminalWindow == 0. but the returnValue is 0 which means that the function call succeeds.
View 2 Replies
View Related
Feb 28, 2011
I was trying to get the ssid of WLAN through the following C program
What is the cause of this error?
View 1 Replies
View Related
Jan 11, 2010
I am testing the serial ports on a Single Board Computer(SBC) running Linux kernel 2.6.29. I usually do this by connecting the serial port to another PC serial port, then doing "cat /dev/ttyS0" on PC and "echo hello > /dev/ttyS0" on the SBC. However in the current system, "echo hello > /dev/ttyS0" command does not return at all! Also no characters appear on the destination port. I am running the echo command as root. The system boot messages show that the serial port in indeed /dev/ttyS0.
View 2 Replies
View Related
Feb 18, 2011
How can I pass carriage return to a command in the shell script. I am writing a shell script whcih generates ssh key pair. It ask for input from user three times. I want to pass carriage return (i.e., press Enter button) to this command.
View 2 Replies
View Related
May 18, 2011
How to manage the find command to return true or false if a file was found/or not? I tried to man find but didn't found anything.
View 12 Replies
View Related
Oct 12, 2010
The first line of this struct:
Code:
struct custom_int {
typedef int big_int;
[code]...
View 4 Replies
View Related
Jan 18, 2011
I just want to read and write some values (integer) to my driver. I used put/get user but always getting errors.
driver
Quote:
int Wert;
static int device_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsinged long arg)
int ret;
[code]...
Quote:
int WERT
ret=ioctl(fd, SETIT, WERT)
ret=ioctl(fd, GETIT, WERT)
if i say in C++ WERT is 5 the value arg of the driver becomes 5 but not WERT the returnvalue of get and put user is -1 so it failed.
View 12 Replies
View Related
Feb 12, 2010
Hi I am trying to add the device by using followig code strip and it says that eth1 is not defind in the code.
strncpy(ifr.ifr_name,eth1,IFNAMSIZ);
if (ioctl(sd, SIOCGIFINDEX, &ifr) == -1) {
return 0;
}
How do I write down the DEVICE name in the ifr.ifr_name structure ?
View 2 Replies
View Related
Apr 6, 2011
I am having the following problem. The following code works fine on my P.C. Ubuntu x64, and on a jetway mini-itx board with an atom processor. The problem is, the same code doesn't work on the intel equivalent of the jetway board. I thought the maybe, I didn't have the port configured right, so I turned on Hardware Flow control and also tried turning on the modem bits I needed with TIOCMBIS. Neither worked. Here is the code. There are two threads, one of them, respsponding to the client, and using the RTS and DTR pins to power two relays. The other, manages listening to CTS and DSR for input. Here is the class with the first thread.
Code:
/*
* DigitalIOCore.cpp
*
* Created on: Nov 1, 2010
* Author: jonathan
[code]....
View 9 Replies
View Related
Jun 13, 2010
I'm having some difficulities with truecrypt and cannot figure out what's wrong since this is my first attempt to create hidden encrypted partition. I'm using ubuntu 9.10 64b with latest 6.3a truecrypt. After using truecrypt gui (just command truecrypt) I've tried: create volume-->create volumne within a partition/drive-->hidden trucrypt volume --> select some /dev/sdX by my choice --> select aes & sha512 --> password --> and format it.
when formating finished message "wrong ss, swith or wrong superblock of /dev/loop0" appeared. I've got no idea what could I do with it neither know whats program trying to do! Ok formating's done, then if you're trying to mount that partition then I would expect prompt for password, but that did not happen ...
EDIT: sudo mount /dev/loop0 /media/tmp/ also complaint about wrong superblock, but that does not ring any bell since i've got no idea what /dev/loop0 is or is for...
EDIT2: I've tried another approach also:
sudo truecrypt -t -c
sudo truecrypt -t /dev/sda3 --filesystem=none
but the first command finished creating 100G drive in 1 sec (nonsense) and latter one prints:
Error: device-mapper: reload ioctl failed: Invalid argument
Command failed
View 3 Replies
View Related
Dec 5, 2010
The error message I keep getting during mounting is:-
device-mapper: remove ioctl failed: Device or resource busy
This is from ane external USB HDD I use as a backup device. I've tried formatting it as ext4 ane encrypting it from the command line
# mkfs.ext4 /dev/sdc1
# cryptestup luksFormat /dev/sdc1
which run without errors but an attempt to mount throws up the above error as well as saying - you must specify the file type (tried that) - and fails to mount. I've tried using YaST to format and encrypt it which throws up the same error when I run mount but actually does actually mount the filesystem Googling around has brought up info saying that it's probably a race condition brought on by invalid udev rules. I've got a (mostly) working system and the udev rules documentation leaves more confused than when I started.
View 8 Replies
View Related
Nov 11, 2010
We make everyday a DB Mysql backup on Linux redhat Enterprise. We are using a bash shell script (and putting it in the crontab) to execute it automatically everyday. We added a line to this script telling, once the backup has completed, to find old backup files (stored on hard disk after each backup) older than x days to remove them. We use the find command (search for file type) with the mtime option and in combination with rm command. Everything runs ok but we also want to add some new code to the same line: If find command cannot find anything or fails, for example if it cannot delete file or fails, send the error message (standard error output) to an error file (like error000001 and increasing) and mail the errorxxxx file to an email address for example to admin@companyname.com. What would be the code for this issue to add it to our find command in the same bash shell script??
View 2 Replies
View Related
Jun 30, 2010
I trying to write a UART(interfacing of serial devices) to linux machine but after I execute the following code to receive data I need to enter key (carriage return).... but I don't want to remove carriage return/enter key
[Code]....
View 13 Replies
View Related
Jan 13, 2010
I'm trying to get a return value from the command running within screen. I have tried
Code:
screen "some_command ; echo $? > retval"
but this refuses to write "retval".
[code]....
View 1 Replies
View Related
Nov 7, 2010
What is a Linux command that I can run to programmatically return either 32 or 64 to indicate whether the processor is a 32 bit or 64 bit processor?
View 4 Replies
View Related
Feb 19, 2010
I am writing a short script to do some backups.Here is a small section of it:
Code:
echo -n "Please enter your choice ..."
read CHOICE
[code]....
View 3 Replies
View Related
May 2, 2011
getting a error return code for useradd commandthe return code is 1cite or tell me the explanation of return code 1 .
View 1 Replies
View Related
Mar 31, 2011
I need to get a return code for the command ldapmodify.I try this and didn't workrc=ldapmodify -a -v -c -p $PORT -h $SRV -D cn=$USR,cn=Users,dc=company,dc=com -w $PWD -f $LDIFFILENAMECOUNTecho "return code " $rc what exactly the way to get the return code of that ?
View 2 Replies
View Related
Feb 18, 2011
How can I pass carriage return to a command. I am writing a shell script whcih generates ssh key pair. It ask for input from user three times. I want to pass carriage return (ie. press Enter button) to this command. Is tehre any way
View 8 Replies
View Related
Nov 25, 2010
Below is an example output of what I see when I run the 'ls' command on some directories in linux (this is from a tomcat/common/lib directory). However I'm not clear on why some of the filenames are appearing inside [square brackets]
-rw-r--r-- 1 root root 1038825 Aug 30 2006 [ant].jar
-rw-r--r-- 1 root root 566376 Apr 1 2008 [commons-collections].jar
-rw-r--r-- 1 root root 107392 Aug 18 2006 [commons-dbcp].jar
[code]...
View 2 Replies
View Related
May 25, 2010
Normally one can start the Jboss with
Code:
./run.sh -c server-name
But in this way the command console will keep hang. Now I want to write a script which calls u this command and return back to the command console. Here is what I wrote but it doesn't return back to the command console:
Code:
#!/bin/sh
MSGBP_HOME="/opt/jboss/MSGBP"
case "$1" in
start)
[code]...
View 1 Replies
View Related
Jan 17, 2011
To put it simply I want the egrep command to return matches for a group rather than the whole pattern itself.For example:
Code:
egrep "reals([0-9]+?m[0-9]+?.[0-9]{3}s)" tmp
returns
"real 0m1.001s"
But I want it to return just "0m1.001s", the portion is the group. I can just apply egrep to whatever the first command returns but is there an easier way to do it?
View 4 Replies
View Related
Aug 3, 2010
Essentially my ksh script calls a program and passes some commands. It's entering the program just fine, but when it passes the commands it gets "invalid command" error, and loops for a bit.
When I run all the steps manually the program works fine. I turned debug on and see that it enters the program, cmbview, but for whatever reason, it fails on any command that it tries to parse.
Tried running it in a ksh shell, same error. Tried running it as bash shell, same error.
The cmbview exe works and the following commands work, so I can only assume its something with the script parsing the commands.
View 2 Replies
View Related
Oct 12, 2010
i am having two small issues with a function i have made.sorry if it is a mess, i am still learning bash.the first is calling the nonpersistssh function (second line) and assigning the return value to nonpersistdiag.the function returns 1, but nonpersistdiag seems to only contain 0. i am unsure on how to proceed.the second problem is the nested else clause on line 10. it is a syntactical error. how would i declare it correctly?
Code: function endsession(){
nonpersistdiag=$[nonpersistssh]# a function that returns an exit code
sudo /etc/init.d/ssh stop; sshdiag=$?
[code]....
View 6 Replies
View Related
Jun 3, 2011
What are the uses of return 0, return 1 and exit statements in C
View 4 Replies
View Related
Nov 15, 2010
On this link [URL]4 a return type is defined
Code:
return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG);
What is the above function returning.I am not clear with definition of what is being returned in the above code.
View 7 Replies
View Related
Jan 18, 2010
I'm confused about what "echo $0" in a shell actually return. Consider these tests:
Code:
[root@e11apvl151 ~]# # Login shell:
[root@e11apvl151 ~]# echo $0
-bash
[root@e11apvl151 ~]# # Starting a new shell
[root@e11apvl151 ~]# bash
[root@e11apvl151 ~]# echo $0
bash
[root@e11apvl151 ~]# screen
[root@e11apvl151 ~]# echo $0
/bin/bash
Depending on wether the shell is a login shell, a regular shell, or a screen utility, I get different results.
View 8 Replies
View Related
