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--- tips:threelinestip [2008/04/19 11:49]
a + How do I capture the output of “top” to a file?
+++ tips:threelinestip [2009/05/25 00:34]
127.0.0.1 external edit
@@ Line 37: / Line 37: @@
 export MAKEFLAGS="-j3"
+=== Patch & Diff ===
+   $ diff -c prog.c.old prog.c > prog.patch
+   $ patch < prog.patch
+=====  Printing network traffic =====
+   % sudo tcpdump -Atq -s 0 -i en1
+-i en1 will display traffic on your airport card. Use en0 (or nothing, for most systems) for built-in ethernettage. You can add a host line to limit output to a particular host
+   % sudo tcpdump -Atq -s 0 -i en1 host foobar.com
+===== Couting openfiles per user =====
+   # lsof | grep ' root ' | awk '{print $NF}' | sort | wc -l
+Of course, if you want to drop the count and show the actual processes, you can run:
+   # lsof | grep ' root '
+===== How to check is service is tcpwrapper enable =====
+   # ldd `which sshd` | grep -i libwrap
+or
+   # strings `which sshd` | grep -i libwrap
+===== Comparing files & taking some action based on outcome =====
+**Method 1**
+<code>
+cmp -s file1 file2 || {
+  # do something
+}
+</code>
+**Method 2**
+<code>
+cmp -s file1 file2
+if [ $? = 1 ]
+then
+  # do something
+fi
+</code>
+===== IPv4 parsing / sorting =====
+   egrep '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}'
+and
+   sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4
+===== finding a string in a "live" stream =====
+tail -f filename |grep --line-buffered  STRING
+===== Local/remote webserver =====
+Serve files on port 8080 for anybody from the directory from where you start this command:
+<code bash|>
+:;while [ $? -eq 0 ];do nc -vlp 8080 -c'(r=read;e=echo;$r a b c;z=$r;while [ ${#z} -gt 2 ];do $r z;done;f=`$e $b|sed 's/[^a-z0-9_.-]//gi'`;h="HTTP/1.0";o="$h 200 OK\r\n";c="Content";if [ -z $f ];then($e $o;ls|(while $r n;do if [ -f "$n" ]; then $e "<a href=\"/$n\">`ls -gh $n`
+";fi;done););elif [ -f $f ];then $e "$o$c-Type: `file -ib $f`\n$c-Length: `stat -c%s $f`";$e;cat $f;else $e -e "$h 404 Not Found\n\n404\n";fi)';done
+</code>
+===== resolving IP Addresse (nmap) =====
+<code bash|>
+nmap -sL $1 2>/dev/null |
+perl -ne 'print unless /^Host [\d.]+ /' |
+grep 'not scanned' |
+cut -d ' ' -f 2,3 |
+sed -e 's/\(.*\) (\(.*\))/\2 resolves to \1/'
+</code>
+output:
+<code>
+.133.219.10 resolves to fed.cisco.com
+.133.219.11 resolves to asp-web-sj-1.cisco.com
+.133.219.12 resolves to asp-web-sj-2.cisco.com
+.133.219.13 resolves to fedtst.cisco.com
+.133.219.14 resolves to www.netimpactstudy.com
+.133.219.15 resolves to deployx-sj.cisco.com
+.133.219.16 resolves to contact-sj1.cisco.com
+.133.219.17 resolves to scc-sj-1.cisco.com
+.133.219.18 resolves to scc-sj-2.cisco.com
+.133.219.19 resolves to scc-sj-3.cisco.com
+.133.219.20 resolves to jmckerna-test.cisco.com
+.133.219.21 resolves to events.cisco.com
+.133.219.22 resolves to bam-prod-1.cisco.com
+.133.219.23 resolves to redirect.cisco.com
+.133.219.25 resolves to www.cisco.com
+.133.219.26 resolves to partners.cisco.com
+</code>
+===== Linux Get Hardware Serial Number From Command Line  =====
+   dmidecode |grep -i serial
+===== Convert pdf to jpg =====
+  for file in `ls *.pdf`; do convert -verbose -colorspace RGB -resize 800 -interlace none \
+    -density 300 -quality 80 $file `echo $file | sed 's/\.pdf$/\.jpg/'`; done