I have following script.
Code:
#!/bin/bash
export VAR="shell"
echo " $VAR in parent "
bash
echo "shell in child "
If i execute this script, the output is just
Code:
shell in parent
Why can't I see the output shell in child ?
I am troubleshooting something and I got this problem.
If I do "pstree -p"
It shows,
Code:
[code]....
However, it does NOT show up in "ps -elf"
Code:
ps -elf | grep soffi
0 S whho 7734 1 0 80 0 - 36435 - 11:14 pts/2 00:00:03 /usr/lib/openoffice/program/soffice.bin -splash-pipe=5
0 S whho 7833 7759 0 80 0 - 751 - 11:21 pts/3 00:00:00 grep soffi
I was wondering if 7735, 7736, 7737, 7743 were really processes. Then I checked /proc, I could cd to /proc/7735, /proc/7736, etc, but I could not ls them out. I looked at the man page of "pstree", it says,
Code:
Child threads of a process are found under the parent process and are shown with the process name in curly braces, e.g.
icecast2---13*[{icecast2}]
So, what does all this mean? Does it mean that 7735, 7736, 7737, 7743 are just threads but not processes? If so, why could I cd to /proc/<id> but not see them in "ps -elf".
I am developing a application. In this I fork() 3 childs(lets say child1 , child2, child3) . The parent is now waiting for some input from keyboard.Child3 is continously getting data from child1 and child2 using pipe which it then will print using printf.Now as the parent is waiting for input from user through keyboard while child3 is continously printing the data. I want to do it in different terminals.Can you please guide me how to proceed ahead so that on one terminal , the parent waits for input fromser while on other terminal child3 prints data.
View 1 Replies View RelatedI'm in a nested shell trying to use disown to re-root myself as well as a child. Looks like this:
Code:
# echo $$
1234
# disown 1234
disown: job not found: 1234
# disown $$
disown: job not found: 1234
# pgrep mychild
2222
# disown 2222
disown: job not found: 2222
This is in zsh. The goal is to have process 1 (the root of all processes) to become the parent.
How can I pipe the output of a shell command into a new buffer in Vim? The following obviously wouldn't work, but you can see what I'm getting at:
:!echo % | :newtab
I often have issues starting my window manager--xfce. My computer misbehaves in one of 3 ways, one of which is to fail to open X, but generate several screens of info. I want to paste that info to this site, but since I'm in the shell, not the terminal (please correct my vocabulary if it's wrong here), I don't know how to copy and paste the output, since right-clicking doesn't give me a menu. Even if I could copy I'm not sure the information would be accessible in X. Are there any other options?
View 13 Replies View RelatedOn command line I have no problem storing a variable e.g
Code:
:~/bin$ process=`ps -ef | awk ' $8 == "idesk" { print $2 }'`
:~/bin$ echo $process
26736
:~/bin$
When I try to incorporate this into a shell script I get a blank.
Code:
:~/bin$ cat process_idesk
#!/bin/bash
process=`ps -ef | awk ' $8 == "idesk" { print $2 }'`
[code]....
The process_idesk script has been chmoded to be executable by the user. I'm sure there must be a silly omission on my behalf.
Before I begin I would like to say that while I am not a Linix newbie, I am not a guru or even a regular user so don't assume I have anything more than general Linux knowledge. I am carrying out research involving virtualization and Single Sign On technologies and I need to display a Xen based virtual machine to the desktop before the user is logged in. This is for a demonstration system and I am trying to find a solution that involves the least amount of system modification possible.I found a PAM module that allows for the invocation of arbitrary shell scripts which would allow me to start and display the virtual machine in question, but when trying to run the virt viewer (or any process with graphical output) I am informed that the display cannot be found. Explicitly setting the DISPLAY env to :0 before running the command has no effect.
This is where my Linux knowledge runs out. I know that there has to be some way to connect to the X session being used by the greeter, I just don't know what that method involves. The shell script is running with root privileges, so it can access whatever "X credentials" are stored locally.
I will be thankful for any assistance this forum might be able to provide, but please do not suggest alternatives to displaying a VM for my SSO needs, and please avoid any solution that involves having to write my own custom greeter. If there is absolutely no way to accomplish what I am trying to do without greeter modifications definitely tell me, but I am a security researcher, not a Linux developer so I am looking for the easiest solution to implement, even if that solution is a gross hack.
Regarding this task, I am able to print colored output in my putty sessions using tput or ASCI codes but whenever I tried to send that output through mail command to my outlook maillox, It always goes without colored. I need to produce those coloured output of the scripts as it is in mail.
View 1 Replies View RelatedI am writing a script in which I am using AWK to append to a line in a file and save the file. The command I am using is:
Code:
awk '{s=$0; if ( NR==4 ){s=s ":/usr/java/jdk1.6.0_19/bin" } print s;}' $appName > $appName.new
[code]...
I want to write expdp output in a text file using a shell script
If i write like below:
It will write whatever is there in log file to text file
But, sometimes export fails with out start taking export (without generating log file) because of job already exists error. such times, we dont know about that error until we check manually... so i wrote like below:
But still it is not writing anything in to text file using above stmt...
I have a doubt about signals in C programming. I have done this little program to explain it. It creates a child process with fork and, when the child ends, receives the SIGCHLD signal and wait for its termination.Ok, quite easy, BUT when I execute this code the SIGCHLD signal is received twice, first as an error (returns -1) and the second one to finish the child process.I don't understand the meaning of the first received signal. Why is it generated? Is the code wrong? (if you add the SIGINT and press Ctrl+C during the execution it also receives two signals instead of one)
Code: #include <stdio.h>
#include <unistd.h>
#include <string.h>
[code]....
How to get output of text file containing account number, debit amount, credit amount,date using shell script?
View 1 Replies View RelatedConsider the following code:
Code:
int main()
{
int i=0;
pid_t pid;
for(i=0;i<2;i++)
[code]....
I get the following output:
Parent: chid_pid=4356 i=0 parent's pid=4355
This is child 4356 i=0
This is child 4357 i=1
[code]....
I can observe instead of two children(as I expect) processes there are three. This is because child process 4356 creates its own child. Why all the messages of the type "This is child X i=Y" are concentrated one under another? How exactly fork works? Is affected by the fact that I have a dual-core processor?
how would you go about piping the output of the shell to notify-osd?
View 5 Replies View RelatedI write LaTeX in Emacs and then run a shell script to process the LaTeX code. I used to run a subshell buffer with M-x shell and then execute the script from within there, but this results in a lot of switching between buffers, which seems unnecessary. Then, I found out about executing shell commands with M-! cmd RET, as described here:[URL]The problem with this is that the output from the script splits my screen. It's a nuisance, and I would like to run the script without any output. I've tried appending > /dev/null to the command, but it doesn't work.For example, when from within Emacs I enter M-! followed by
Code:
sh make.sh > /dev/null
it splits my screen so that one portion displays output from the make.sh script. I want it to run silently, and leave my Emacs buffers alone
I have a huge database of students, I would like extract these data and write to individual file for each students.
I am running a loop in shell program (.sh file), the output of each run in the loop need to redirected to a file with variable name.
I tried the following line, but it did not work, where BodyMsg is the data and Rollno is the students roll number.
echo $BodyMsg > $RolNo".html"
I'm running RHEL5.5 and nagios 3.2.0. The real question deals with how to change the printed output so nagios will work with it.I have made a script that will calculate network throughput on interfaces. The script is going through and finding all interfaces (eth, bond, lan) and doing the math to calculate throughput.The output is mainly for nagios to report and trend the values. As nagios wants to see nothing but perf data after the '|' character, I somehow need to have only one '|' character for all of the output.
View 2 Replies View RelatedThis is an extremely weird issue that I can't find any help with on Google. It is minor but extremely annoying.
When I type in a linux command in the terminal, (e.g. "ls -la"), and then press enter, the cursor goes to the next line and just sits there, as if its processing some long command.
If I press enter again, I see the ls output as well as my prompt twice. It's like the terminal window isn't auto-scrolling, but I've also seen this happen when there wasnt even enough text in the console screen to warrant a scrollbar. Has anyone seen this before and know what I need to do? I hope what I'm asking about makes sense.
I did a select on my db and now I need that this if consult return true for me salve the columns information in file. How I do this in Shell?!
View 3 Replies View RelatedI use tcl-expect script to ssh to the server. How can I eliminate the first 2 lines if using system(./script.sh) to execute it, as the default output will be shown on shell and the first 2 lines are included.
Essentially I just want to have the "ps" result, not the login process. code...
I have a command that outputs n lines of text, and I want to place each line into an array element, but I can't seem to get the syntax correct
So my command is this:
cat $configfile | sed -n '/cluster:'$clustername'/,/cluster/ p' | awk /host/
Which produces many lines depending on the value of $clustername. I'd like to get each line as elements of an array.
I'm trying to write a script that uses the 'du' command to make essentially a text-based filelight type program. It should scan the current directory for the file's sizes and display them in order largest to smallest (or vice versa). The user should be able to go throughout the file tree and see child directories scanned for the sizes as they're accessed. I just need to know one more thing- how can I restrict the displayed results to the current working directory? would a grep for the output of pwd suffice? just getting some thoughts before i try and possibly dig myself a hole.
View 1 Replies View RelatedWhat happens to a child process that dies and has no parent process to wait for it and what's bad about this?
View 2 Replies View RelatedIn my program, I fork() to get a child process. Because of some problem, child process terminates by a segmentation fault. Parent process is still running. I have compiled my code with -g option. I have done: ulimit -c unlimited. I am not getting core dump of the child process. How can I get the core dump of child process?
View 1 Replies View RelatedI have created three child process from one parent. And different child has different functions. Child 2 has got function to load file called "wc" to count file1 and and its required to get their files by command line arguments. I can get the files through command line but couldn't get the files when child 2 process start.
View 9 Replies View RelatedI want to check all the child processes attached to a specific process. Say for a example; my process is a java process. Then I wanna know what are the processes attached to that java process. At the moment I use the command # ps aux|grep java; this gives the details about the currently running java process. So I can kill the whole java process using #kill -9 {pid} ...but there are sub processes attached (I guess child processes) to java process. I wanna view all of them & kill whatever the process I like not the whole thing. I'm using Red hat 5 enterprise edition. and currently a weblogic application server is running on that.
View 2 Replies View RelatedI work on Linux for ARM processor for cable modem. There is a tool that I have written (as the job demands) that sends/storms customized UDP packets using raw sockets. I form the packet from scratch so that we have the flexibility to play with different options. This tool is mainly for stress testing routers.I actually have multiple interfaces created. Each interface will obtain IP addresses using DHCP. This is done in order to make the modem behave as virtual customer premises equipment (vcpe).
When the system comes up, I start those processes that are asked to. Every process that I start will continuously send packets. So process 0 will send packets using interface 0 and so on. Each of these processes that send packets would allow configuration (change in UDP parameters and other options at run time). Thats the reason I decide to have separate processes. I start these processes using fork and excec from the provisioning processes of the modem. The problem now is that each process takes up a lot of memory. Starting just 3 such processes, causes the system to crash and reboot.
I have tried the following:-
1-I have always assumed that pushing more code to the Shared Libraries will. when I tried moving many functions into shared library and keeping minimum code in the processes, it made no difference to my surprise.
2-I also removed all arrays and made them use the heap. However it made no difference. This maybe because the processes runs continuously and it makes no difference if it is stack or heap?
3-I suspect the process from I where I call the fork is huge and that is the reason for the processes that I make result being huge. I am not sure how else I could go about. say process A is huge -> I start process B by forking and excec. B inherits A's memory area. So now I do this -> A starts C which inturn starts B will also not help as C still inherits A?. I used vfork as an alternative which did not help either. I do wonder why.
I am having a hard time getting conky execp/execpi to correctly parse output of the scroll variable generated from shell or PHP scripts.
Code: Select allDebian 8.0
Xfce 4.10
Conky 1.9.0-6
This is a simplified minimal conky configuration file used to show the same problem:
Code: Select allalignment bottom_middle
background no
border_width 1
default_color white
default_outline_color white
default_shade_color white
double_buffer yes
[Code] ....
Here is the output I'm getting:
Code: Select all ABC /*doesn't scroll, UNEXPECTED, shows 10 spaces before ABC*/
ABC --||--
abcdefghijklmnopABC /*doesn't scroll, WORKS AS EXPECTED as scroll length is 25 which is longer than text "abcdefghijklmnop" */
abcdefghijklmnopABC --||--
abcdefghijklmnopABC /*WORKS, everything before ABC scrolls 5 characters at a time*/
Recently I have renovated an old computer which once belonged to my dad (the old HDD crashed, and I just bought a new one to replace it). My parents want me to fix this computer for my 5-year-old sister to use. I decided to use Linux Mint as the OS because everything (flash, mp3, etc.) is already configured.
How do I create a user account in Linux Mint with limited access for my sister, so that it won't mess up the entire system?
All she does is surf the web, so I'm just worried that she might accidentally mess up a system setting that I eventually will have to fix it.