bash
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bash [2013/05/08 17:53] k2patel [Bash Tips / Tricks] |
bash [2019/08/21 21:26] k2patel |
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| </code> | </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 ==== | ==== Control case ==== | ||
| Line 366: | Line 377: | ||
| === Truth Table === | === Truth Table === | ||
| - | 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> |
| + | These two commands not the same: | ||
| - | We can actually run through all four possibilities. Here's the command (I wonder whether this will get through unscathed?): | + | 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; $c2) || echo c3; done; done | for c1 in true false; do for c2 in true false; do echo "$c1 && $c2 || c3"; (echo c1; $c1) && (echo c2; $c2) || echo c3; done; done | ||
| + | </code> | ||
| And the output: | And the output: | ||
| Line 389: | Line 413: | ||
| c3 | c3 | ||
| </code> | </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 ==== | ==== Networked Info ==== | ||
bash.txt · Last modified: 2020/08/10 02:35 (external edit)
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