commandline session $ 4.2.36 8 508—> reportbug –debug Please enter the name of the package in which you have found a problem, or type ‘other’ to report a more general problem. > testing *** Welcome to reportbug. Use ? for help at prompts. *** Note: bug reports are publicly archived (including the email address of …
Author Archives: jeffrin
HACKS AT LINUX KERNEL
Linux(kernel) System Administration 1. Memory Management – Virtual Memory Using /proc/sys/vm
TOOLS PLAN
Project Diagram
GNU bash –noediting and -v
commandline session $ 4.2.36 5 505—> bash –noediting $ 4.2.36 1 501—> tcp bash: tcp: command not found $ 4.2.36 2 502—> $ 4.2.36 2 502—> exit exit $ 4.2.36 6 506—> tcprobe $ 4.2.36 16 516—> bash -v # System-wide .bashrc file for interactive bash(1) shells. # To enable the settings / commands in …
/proc/meminfo related
# cat /proc/meminfo MemTotal: 1995608 kB MemFree: 77804 kB Buffers: 226640 kB Cached: 306916 kB SwapCached: 1256 kB Active: 817952 kB Inactive: 458696 kB Active(anon): 553568 kB Inactive(anon): 193212 kB Active(file): 264384 kB Inactive(file): 2100484 kB Unevictable: 4696 kB Mlocked: 4696 kB SwapTotal: 5843964 kB SwapFree: 5838604 kB Dirty: 752 kB Writeback: 0 kB AnonPages: …
SHLVL – Incremented by one each time an instance of bash is started
commandline session $ 4.2.36 2 501—> echo $SHLVL 1 $ 4.2.36 3 502—> echo $SHLVL 1 $ 4.2.36 4 503—> bash $ 4.2.36 1 500—> echo $SHLVL 2 $ 4.2.36 2 501—> logout bash: logout: not login shell: use `exit’ $ 4.2.36 3 502—> exit exit $ 4.2.36 5 504—> echo $SHLVL 1 $ 4.2.36 …
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BASH_VERSINFO A readonly array variable
commandline session $ 4.2.36 2 501—> echo BASH_VERSINFO[0] BASH_VERSINFO[0] $ 4.2.36 3 502—> echo $BASH_VERSINFO[0] 4[0] $ 4.2.36 4 503—> echo $BASH_VERSINFO 4 $ 4.2.36 5 504—> echo $BASH_VERSINFO[1] 4[1] $ 4.2.36 6 505—> echo BASH_VERSINFO[1] BASH_VERSINFO[1] $ 4.2.36 7 506—> echo “BASH_VERSINFO[1]” BASH_VERSINFO[1] $ 4.2.36 8 507—> echo BASH_VERSINFO(1) bash: syntax error near unexpected …
sar – Collect, report, or save system activity information
commandline session $ 4.2.36 24 220—> sar -b 1 3 Linux 3.2.0-3-amd64 (debian) Saturday 29 September 2012 _x86_64_ (1 CPU) 01:22:03 IST tps rtps wtps bread/s bwrtn/s 01:22:04 IST 0.00 0.00 0.00 0.00 0.00 01:22:05 IST 0.00 0.00 0.00 0.00 0.00 01:22:06 IST 5.21 0.00 5.21 0.00 2541.67 Average: 1.71 0.00 1.71 0.00 832.76 $ …
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tcpdump not port 80
commandline session root@debian:~# tcpdump -i wlan0 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on wlan0, link-type EN10MB (Ethernet), capture size 100535 bytes 23:33:46.824172 IP debian.local.48247 > mars.infoclub.in.http: Flags [S], seq 1276297543, win 14600, options [mss 1460,sackOK,TS val 4098743 ecr 0,nop,wscale 5], length 0 23:33:46.826612 IP debian.local.41745 > 192.168.0.1.domain: 43954+ …