please use following steps.
# ~$ mkdir temp
# ~$ cd temp
# ~/temp$ cp ~/x.deb .
# ~/temp$ ar x x.deb
# ~/temp$ tar xf data.tar.gz
June 14, 2011
extracting files from deb to temporary directory.
December 31, 2010
December 17, 2010
coding guidlines
)1) while coding it;s better to maintain single return statement when method/function handles critical sections and uses locks or other synchronization mechanism
(2) in case of C++, use ++ instead of ++. ++ is more efficient when compared to ++ because post increment will result in copy constructor getting called while pre-increment will not.
(3) it’s always better to initialize the member variables of class as part of class construction using member variable constructors.
December 7, 2010
September 22, 2010
tracking proc using strace.. and specific fd
/proc/9533/fd/socket:[505625660]
root@topaz:/var/cae/log# netstat -anp | grep Sys | grep 505625660
unix 3 [ ] STREAM CONNECTED 505625660 9533/SystemMgrCae
root@topaz:/var/cae/log# strace -p 9533
Process 9533 attached – interrupt to quit
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29287) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=35, u64=35}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 35, {EPOLLERR|EPOLLHUP, {u32=35, u64=35}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
read(35, “=”, 4) = 4
read(35, “\203h\fa(a\10a\2a\10m\5admind\3clia\2h\4a”…, 61) = 61
write(35, “\16\203h\4aZa\10a\2d\2ok”, 18) = 18
epoll_ctl(3, EPOLL_CTL_MOD, 35, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=35, u64=35}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 27159) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 27159) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=49, u64=49}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
recvfrom(49, “A”, 1, MSG_DONTWAIT, NULL, NULL) = 1
write(5, “”, 1) = 1
write(5, “”, 1) = 1
recvfrom(49, 0x7fff30052820, 1, 64, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(3, EPOLL_CTL_MOD, 49, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=49, u64=49}}) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 3
write(5, “”, 1) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3, {{EPOLLIN, {u32=4, u64=4}}}, 128, 29999) = 1
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
read(4, “”, 1024) = 1
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
epoll_wait(3,
Process 9533 detached
August 16, 2010
web polygraph load testing
Following tcp and ip parameters would help to get high load tests with less/no connection failures from poly server and poly client.
make sure to set these values on both the systems.
echo 1000 64000 > /proc/sys/net/ipv4/ip_local_port_range
echo 10 > /proc/sys/net/ipv4/tcp_fin_timeout
echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle
echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse
Please save your self my backing the current setting for reference.
July 9, 2010
AWK scripting example
the following awk could help you to process file content after certain line-number.
does matching and apply conditions.
cat audit.log | awk ‘ BEGIN { i=0;found=0} { i=i+1; if ( i >= 2430344 ) { regex1=”userGroup”;regex2=”pcl”;result1=0; result2=0; result1=match($9,regex1); result2=match($9,regex2);if ( result1 || result2) { found=1; };regex3=”exit”;result3=0;result3=match($9,regex3); if ( result3 && found) { print $_;found=0 } if (found) { print $_ } } }’ > /tmp/cli.txt
July 1, 2010
using tshark for watching protocol traffic
most of the telecom/wireless network elements in deployment don’t have X-windows on them installed and will just have core linux kernel installed.. and sometime we want to watch particular protocol details on network elements which don’t support X-windows, which means we can not use wireshark.
tshark helps to get this going..
you can watch live traffic using tshark command.
tshark -i -R
for e.g. tshark -i any -R sctp would help you to watch sctp traffic live hitting the box on all available interfaces on system
May 27, 2010
dpkg useful options.
dpkg -L lists all files installed as part of the package on system
dpkg -S searches all packages and lists the package(s) which have installed the file.
December 4, 2008
collecting url list from web…
i wanted to collect random urls from net… and this post talks about my current dirty way of doing so.
(1) Visited http://www.adddirectoryeasy.com/ and collected the source pages and executes following command;
(2) grep “a href=” web-sites.txt | grep “target=\”_blink\”" | awk ‘{ print $2 }’ | grep -v src | cut -d’=’ -f2 | cut -d’”‘ -f2 | uniq | wc -l > websites.txt
