I have a function in perl which I want to use trap all errors a script ocurs which the script does not explicitly handle. These errors are then logged to various places. So I tried to use a eval block but the problem I have is sometimes if you put a die statement in the evaled script it doesn't get handled. What I have so far is:
[Code]....
I have a script that that is supposed to send me an e-mail when a host is not responding to ping:
The script works fine when I execute it directly but when cron executes it, the ping error is never picked up by the script so the if statement is ignored.
Code:
#!/bin/sh
onexit()
{
echo "Error At line - $1"
}
[Code].....
What I want to do is to make the onexit function to handle any generic error that comes during script execution. I am not thinking about using 'set -e' since it will cause a quick exit. I did 127, because I wanted my script to handle atleast the command not found error. I am not thinking about handling any interrupt or any other signal at the moment.
#!/bin/sh
trap "echo Haha" SIGUSER1
echo "asit"
count=1
while [ $count -le 10 ]
do
echo "Loop #$count"
sleep 10
count=$[ $count + 1 ]
done
echo "This is the end"
Why this is showing following error?
trap: 3: SIGUSER1: bad trap
I feel there's a bit of a misunderstanding going on between C++ and me...My problem is that I have a deque of pointers to a class, and create objects then add them to the deque in a for loop. However, the destructor is called on the object as soon as the loop quits.
Code:
This prints:
Code:
Now, if I change the deque from deque<Test*> to deque<Test> then it works fine - I get:
Code:
However, I can't do this with my actual code, because I am creating a deque of pointers to an abstract class, so it won't let me instantiate the class. (This is all so that I can take advantage of polymorphism, and call functions on a set of similar objects without worrying what type of object I'm dealing with).
So, I suppose my question is: what is the correct way to create that deque of pointers to the abstract class? I don't seem to be barking up the right tree currently.
I am running Valgrind on my program. It shows me two errors but mentions only addresses against them and not actual code even on a debug build.
The output is
==23002== Memcheck, a memory error detector.
==23002== Copyright (C) 2002-2005, and GNU GPL'd, by Julian Seward et al.
==23002== Using LibVEX rev 1575, a library for dynamic binary translation.
[code]....
Sometimes the variables will be 0 and sometimes not, and of course the output may also be 0%...What is the best method to handle division by zero errors in awk.
View 2 Replies View RelatedI would like to make program that reads a *.TXT file and searches for last line and constatly refreshing the search. So last line would look something like this:Mike Had A 100.0 Pound Shark.So there are multplie category of "fish"(Shark, Dolphin, etc.) and each of them have allowed weight (ie. minimum 70.0 Pound Shark, 50.0 Pound Dolphin). If in the found sentence Shark or Dolphin doesn't meet requierments than program named False.exe should be started. I dont know how to make it my self so any help is much appreciated. My knowledge on programming is very low but I'm opend for learning.
View 1 Replies View RelatedI want to write simple firefox extension / script or anything to change URLs from HTTP to HTTPS for selected websites (e.g. facebook). That thing is actually bypassing some security checks in my network.
Can anyone tell me how to proceed? I can deal with language as far its C++ or Python (something else would just take more time that's all )
I'm new to php and need some pointers to worth while documentation 'cause I'm getting nowhere I want to make a simple html form that allows me to submit a csv file so that I can work on it.The problem seems to be that if the file is not in the root of the (web) application it won't work.The form doesn't seem to send the path with it so I am unable to (1) know where the file is, I just get the name of the file and (2) I couldn't access the file anyway as it's outside of the apache environment.Is there a way to up the file to memory? How would you do this
View 3 Replies View RelatedI need to make a daemon which listens to port 81 for messages like [URL] So far I made a daemon which serves as a simple stream server: I set up a socket to listen to a non-reserved port (like 9999), but I don't know how to read the query strings.
Linux distro: Kubuntu 9.04
Language: C
I have a file with 200 000 lines and I want to append the fields of each line based on matching first field. The resulting file should have 70 000 columns but has "only" 18 000. The command I'm using is working perfectly with a smaller file, wich lead to 14 000 columns. Could there be a limit in number of fields that awk can handle ? Here's my awk command :
Code:
awk -F, 'END { for (k in _) print _[k] } { _[$1] = $1 in _ ? _[$1] FS $4 : $1","$4 } ' file > out
Also, this command writes ^M (windows line break) after each columns. Removing them is easy but where do they come from ? Working on Ubuntu 10.10
I'm learning Signals, and I have a question:
Is possible to make a handle when I press any of the keyboard buttons?
The SIGINT handles the Ctrl-C combination, but I want to handle if any keyboard button was pressed.
*I'm using Ubuntu 10.10
My issue is I can't handle the files with spaces in their name, I've donde the below script to print each file found inside folder and subbfolders with "find".
I would like to "ls" to each file found with its complete path and with its basename too.
Code:
files=$(find . -type f)
for each in "$files"
do
ls -l "$each" # 1rst option I've tried to list with full path
ls -l "$(/bin/echo "$each")" # 2nd option I've tried to list with full path
ls -l "$(/bin/echo $(basename "$each"))" # 1nd option I've tried to list with it basename
[Code].....
How can I list "ls -l" in both cases (with full path and with basename) when there are files with spaces in their name?
Need to handle SIGSEGV error when pbuf size is less than size. inside lib.:
for (i = 0; i < size; i++)
pbuf[i] = i;
A question of ODBC correctness - maybe someone knows.
Code:
// statement handle is sth, connection handle is dbch
SQLExecDirect(sth, ...);
// ... bind var, fetch results ...
SQLFreeHandle(SQL_HANDLE_STMT, sth); // free statement handle
SQLEndTran(SQLHANDLE_DBC, dbch, SQL_COMMIT);
(error checking removed for clarity).
To my mind this seems wrong - surely the statement handle should be free'd only after the commit is done? Or maybe not. I theorize about the ODBC library like this: a whole set of statements can be created, run, executed in one transaction (which is held at the connection level), and only after all that is a commit/rollback done. So maybe it's OK. Even so it still feels weird. What is written above works, but there are rare and very difficult to replicate problems with this code, and I wonder if a premature free might be the cause...?
how to handle non argument error while adding two alphabets using 'expr' (not bc).
View 1 Replies View RelatedI have made two source files named as sum.c and average.cI have included sum.c in average.c
both files in Documents directory.when i compile average.ot followingerror"average.c:4:22: fatal error: sum.c: No such file or directorycompilation terminated.How to solve this issue?I have tried to copy sum.c to usrinclude folder but unable to copy
I would like to learn the right way, or some neat technique, to discover why a compiled-from-source application just unaccountably quits. it it easy enough to discover that the pre-compiled version from Ubuntu does work just fine. My motivation is to explore, and maybe try to modify it a little for myself.
At my level of programming expertise, I have often used the "sh configure, make, make install" route; and sometimes made small changes to the code eg. changing a window size and similar. C and C++ tutorials teach the main rules, but I am no expert at classes, structures or obscure expression tricks.
The application is a QT type called "qantenna", used for electromagnetic simulation of antennas. The source I downloaded from SourceForge. Although a KDE application, the repository version seems to run just fine on my Ubuntu 9.10 Karmic (soon to become Lucid), on its Gnome desktop.
The compiled version behavior is that the main window opens and runs OK, with the GUI view operating with fully alterable views. As soon as a valid antenna file is loaded, the whole application instantly quits.
How does one deal with an application that gives no chance to catch it doing things wrong?
I'm trying to get SNMP setup so I can send custom snmp trap messages. I followed this "How to" [URL] and I think I have it setup and working. This is my fist time messing around with SNMP, and I don't know where to check to see if I received the trap message. Do the snmp trap message even get logged any where?
View 1 Replies View RelatedQuote: Attackers are constantly changing their tactics and adapting to what the security community and researchers are doing, and it's not unusual for the bad guys to adopt techniques used by their adversaries. The latest example of this is a malware gang that has deployed what amounts to a honeypot designed to monitor the activity of researchers or other attackers who try to access a command-and-control server.
View 1 Replies View RelatedI wounder how I should do to find out what packages I have explicitly installed on the system, NOT including the dependencies. The purpose is to get a figure of what packages I need to install when I reinstall my system.In Gentoo one can look at the world-file (/var/lib/portage/world) which is a list of my explicitly installed packages, not including system packages (located in /var/lib/portage/system)
View 1 Replies View Relatedhow an agent itself generate trap on some particular situation arises
View 1 Replies View Relatedhow can I configure snmp and snmptrap to receive a trap when the used disk (/home/linux) is 20%
View 1 Replies View RelatedI wanted to know is there any way to send a content of a file as snmp trap with snmpd agent of linux?
View 3 Replies View RelatedI run a memory-hungry process (mkcromfs) which consumes more memory than I have physical memory on my latop, so it is paging and swappin and thrashing all the time and loadavg is about 2 (compcache is already in use with usual swap partition as well), but slowly moving forward (Although I afraid it will finally try to allocate >2GB and crash draining 2 days of thrashing).
When I want to use the laptop for something else, I stop the process, start X server, firefox and other programs. The problem is that when I start Firefox the loadavg jumps to 10 and the system becomes almost unresponsive at all (long time to turn on/off caps lock, slow mouse cursor position updates, slow switching from X server to Linux console, slow login).
The stopped mkcromfs still holds a lot of memory (464.8 MiB and slowly falling) and moves it to swap only when more memory is needed for some other program, which results in a great slowdown.
How to tell the Linux to swap out this process entirely (e.g. I'm not intending to resume it in short term), possibly waking from swap other data? Also it will be useful to be able to specify the exact swap device to swap the given process out (for example, mkcromfs's memory is useless in ramzswap).
Update: Now I just write a 400-600M of data from /dev/erandom to tmpfs and it makes mkcromfs to shrink. Is there more proper way?
I used split -b 32m "file.bz2" "file.bz2.part-" to split a file and it created more than 50 parts. From googling, the way I found to reassemble the parts is to cat file.bz2.part-aa file.bz2.part-ab > file.bz2, while enumerating all the 50+ parts. Is there an easier way to reassemble the parts wherein I no longer need to list all those parts explicitly?
I'm using Fedora 12.
Normally I use 'netstat -an' to determine if a daemon is listening on a specific port. The excerpt of this command below doesn't list things like vnc (5900) on ipv4. It does however show it on ipv6. My issue is I want to know how to determine if it is indeed listening on ipv4 as would normally be seen with 0.0.0.0:5900. It would appear that all ipv4 ports are internally being redirected to ipv6. Of course this does simplify things, but it also leaves me unable to reliably determine the ipv4 listening status. How I can tell at a glance if a specific ipv4 port is being listened on? Is there a way to force netstat to list the ipv4 listens specifically?
Code:
art@eee1:/proc/sys/net/ipv6$ netstat -an
Active Internet connections (servers and established) .....
I am attempting to configure my sudoers file, and have quite a few questions.If you can answer any/all of them, I would be grateful.
-Is there a way to set it up so that root gets notified if a user tries to use a command they are not allowed to?
-If something like this already exists on my system, how do I set it up/use it/ read root's messages?
-I see a lecture=always default exists, but can I customize this lecture?
-Is there an easy way to explicitly deny a user sudo permission?
-I see there is an ALL wildcard. Is there something similar to a NONE wildcard?
Is there a command to explicitly park the heads of a particular hard drive?
I have a hot swap tray and want to issue commands to sync and park heads before removal.