Differences

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--- bash [2012/11/28 19:56] – [If File Comparision] k2patel
+++ bash [2020/08/10 02:35] (current) – external edit 127.0.0.1
@@ Line 271: / Line 271: @@
 </code>
+==== Bash alias and complition ====
+Using command completion for alias in bash.
+<code bash ~/.bash_profile>
+alias c='/usr/bin/ssh'
+export HLIST
+HLIST=`cat ~/.ssh/known_hosts | cut -f 1 -d ' ' | sed -e s/,.*//g | uniq | grep -v "\["`
+HLIST="${HLIST} $(cat ~/.ssh/config | grep Host | awk '{print $2}' | grep -v \*)"
+HLIST=$(echo ${HLIST} | sort | uniq)
+complete -W "${HLIST}" c
+</code>
 ==== Control case ====
@@ Line 364: / Line 375: @@
 HISTTIMEFORMAT="[%Y-%m-%d - %H:%M:%S] - "
 </code>
+=== Truth Table ===
+<code bash>
+These two commands not the same:
+command1 && command2 || command3
+if command1
+then
+command2
+else
+command3
+fi
+</code>
+In the if-then-else, exactly one of command2 or command3 will be executed. But in the && || version, command3 runs if either command1 or command2 returns false.
+<code bash>
+for c1 in true false; do for c2 in true false; do echo "$c1 && $c2 || c3"; (echo c1; $c1) && (echo c2; $c2) || echo c3; done; done
+</code>
+And the output:
+<code bash>
+true && true || c3
+c1
+c2
+true && false || c3
+c1
+c2
+c3
+false && true || c3
+c1
+c3
+false && false || c3
+c1
+c3
+</code>
+[[ http://www.linkedin.com/groups/Tuesdays-tip-difference-between-if-3716796.S.236851680?view=&srchtype=discussedNews&gid=3716796&item=236851680&type=member&trk=eml-anet_dig-b_pd-ttl-cn&ut=0FCRGmx_LdW5I1 | Link to Article ]]
 ==== Networked Info ====