General :: What Does The Double Less Than Sign (<<) Means In Creating A New File With Cat
Aug 25, 2010
I saw an article use the following cat command to create a new text file:$ cat > first.sh << ENDAnd then after press the 'return' buttion, a '>' sign appeared expecting you to input the content. If I type 'END' then the 'return' button, then a new text file is created with what I just typed...I'd like to know what's the differnece in just type:$ cat > first.shwithout the '<<' sign?What '<<' really means? I cannot find it's meaning anywere... seems it's not in the redirection section.
Possible Duplicate: Basic ssh tunneling through generic linux ssh server/client. I'm have trouble transfering files again from my work PC, which is a linux machine to my home windows PC.My work has changed it so I now need to SSH twice before I can access my PC.So I need to:
ssh username@server.name password: xxxxx I then need to do it again. ssh computer_name password: xxxxx
I've tried accessing directly via my computers IP but to of no avail. Is there a way I can use pscp or file zilla to ssh twice so I can transfer files?
In the boot process of Linux we have the initrd that is a root file system and is mounted before the real root file system become ready to mount. What is the procedure of mounting? What should happen so we can say that file system is mounted? And another little question why we say ¨root¨ file system instead of just file system?
I have a problem my ubuntu is the latest distro but the shiftkeys are not working like when i whant an @ sign i cant make that sign the keybaord layout has been changed i even have done most of the solutions found on the site and no use.
when ever i try to sign in to my messaging system it gives me this message and wont let me sign in,< Received unexpected response from [URL] useTLS=1 is not allowed for non secure requests.>
I have started on CentOS 5.3 VNC server. I am connected to CentOS from a workstation under control of Windows XP using UltraVNC. Connection passes normally, but I cannot transfer files. By pressing Ctrl+Alt+F7 the message: "The connected VNC Server does not support UltraVnc File Transfer".
I recently had a problem with an absolutely gobsmackingly huge .xsessions-error file growing in my /home partition (over 200 GB--the only reason it stopped growing was that there wasn't any room left). So, I deleted it, and then to see what problems had been causing the file to grow so huge, I rebooted the computer to regenerate it. Big mistake.Since then, I haven't been able to boot. The process hangs when it reaches the step of mounting the /home partition. Luckily, I have my install CD, so I was able to boot into that environment. First, I checked disk integrity--everything was just fine. Then, I tried booting into the liveCD environment. Jackpot! It reports that the bus between /dev/sda6 and itself is timing out when I try to access the former home partition, but I can get into my / partition just fine.I have just edited my /etc/fstab file to *not* know about /dev/sda6, so hopefully it will boot properly (though of course without any access to the files on /home) soon. If this works, I will update.But, does anyone else at all know anything about this sort of problem and what I can do to fix it? Regenerating my /home partition on / merely postpones the problem and doesn't actually get me any of my files back.
UPDATE: Well, that didn't work. Actually, it sort of did, but not quite the way I wanted it to. I was indeed able to bypass mounting the /dev/sda6, but I was not able to boot into Xubuntu since the graphical log-in manager failed and none of the ttys started. The failure mode was, however, interesting. It did not merely fail, but instead flickered violently with a frequency of several seconds until I tried switching to one of the virtual terminals (C-M-!, if anyone is interested).
error message when I ran my program that I couldn't open my local file. I have two files first one is called client, second one is called server I am using named pipes to sent a message from client to the other file called server in client I used mknod() to create the two named pipes,one for read,one for write and created new thread in client using fork() spawned a child process that executed the server file both named pipes are opened the client file got the message from the user and sent it through the named pipes to the server file when the server receives the message , it needs to verfify it is correct in the server file, a local file descriptor is created to read and send this verifing message when it is not correct but I am getting an OPEN() error when I tried to open this shared local array buff and attach it to a file descriptor where the message is kept why do I get this error in server file
int main() { /*both named pipes are open*/ rfd=open(IFIO1,0); wfd=open(IFIO2,1);
can I change the ECC code for a block of a file stored on a flash drive by any means ? of a file stored on a HDD (though I don't think there would be a difference between the two)Maybe , through some hardware interrupts or anything like that?Also if possible I need the solution to be in C/C++.
I have Debian / Ubuntu / Xubuntu. I'm trying to distribute and run a Python file with the least number of clicks for the end user. How do I create a PKG file for Mac OS X on Linux?
create a Cron file and script. I've tried reading through my Linux book but I am just lost here. I need to create a Cron file that will perform a Level 0 backup once per month, a Level 2 dump one day per week, and a Level 5 dump every day that neither a level 0 nor a level 2 dump is performed.
I am calling a service using http post through wget, the command is successfully executing but for each execution its creating a file and saving variable names n data n it. I want to execute this command without creation of a file. Would anyone suggest me what needs to be done in this regard.
My command: wget --post-data 'var1=99&var2=200' http://xyz.example.com:5555/invoke/Samples:httpInvoke For every execution, its creating the files with names: Samples:httpInvoke1 Samples:httpInvoke2 Samples:httpInvoke3
Im using an if statement in the bin ash shell and it isnt working.
Code: if (( 5000 > $available_blocks )) then echo "WARNING Disk space low, "$pct_used" is used" fi
I don't think its a problem with the if. When i use that code it creates a file with name of the value $available_blocks instead of using the '>' sign for comparing the 2 numbers.
would the following command wipe an entire drive clean (partition table included)? Code: dd if=/dev/urandom of=/dev/sda bs=512.I was wondering what the 'bs' part means? Would it be better to omit that?
I want to create a compressed ISO image file and mount that file to one of the virtual drives and access the content (read-only) without worrying about manual decompression/extraction.For Windows and Linux (Ubuntu) OSes.
I want to encrypt Full partition instead of creating a file and encrypting it, and also want to move this disk to another server. do i need some files also (that hold keys) with my self on new server. i am using FC11.
jump into a Linux class in college with only 3 weeks left in the course. I thought I would be able to catch on, and go figure, it didn't exactly happen that way. I was given an assignment to do, and I am so far lost it isn't even funny. I need to create a directory structure, set up file security, create a step by step instruction manual on how to copy/delete said files, and create a guide to common Linux commands. How would I create these files in root and share them with the other users? and where can I find a list of common commands and their functions?
I am trying to use ln to create a hard link to file a and whenever I do it, it creates a copy of the file instead. After having edited file a, when opening the link, it shows the old information and opening file a shows the new information. The command I am using is
Code:
ln /home/user/file
within the new directory i am trying to link from. I am using centos 5.4.
I want to put: xmodmap -e "pointer =3 2 1" somewhere in the startup. It seems creating an .xsession is the solution. But after I create a .xsession file in my home folder, the next time I run startx the screen just turns black. (And only for a short while can I switch to another virtual terminal, before that too becomes impossible). After deleting the file it runs OK again. I'm not using any login/desktop manager. I use IceWM on Debian Squeeze. Is there some script/import that has to be present in the .xsession file, or is something else going on? Also I'd like to know what I should do when I get a black screen. Turning off the PC is such a crude method
I just installed XMMS and I want to create a shortcut on the desktop to run it. I found a how-to video for creating shortcuts so I have the gist of it (I was able to create one for Firefox) but I don't know where to find the executable file for XMMS to do the same. I just don't know enough about Linux's file structure to know where to look.
I'm a Red Hat 6 newbie but have been around Unix.I looked at some threads here regarding this issue and haven't been able to find a solution.I'm executing;
When I look in /var/log/cups/error_log, here's what I get: E [18/Jul/2011:14:37:36 -0700] [cups-driverd] Bad PPD name "/etc/cups/ppd/BR5370_2_GPL.ppd"! E [18/Jul/2011:14:37:36 -0700] copy_model: empty PPD file!
As far as I know, GNOME can't act like MS or OSX when we wan't to rename a file..you know, when you slightly re click the file name and its ready to be renamed.. instead, I should go right click - context menu - rename to do that.
