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sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)

Terminal - sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
se(){ while read a;do [ "$a" != "${a#*$@*}" ]&&echo $a;done ;} # usage: se pattern # use in place of sed /pat/!d where RE are overkill
2011-04-06 03:37:40
User: argv
Functions: read sed
sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)

POSIX requires this "string truncating" functionality.

might as well use it, at least for very small tasks where invoking sed and using RE is overkill.


There is 1 alternative - vote for the best!

Terminal - Alternatives

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What others think

You need to quote "$a" in the echo or it'll drop multiple spaces from the input. e.g.

echo "a b"|se a

a b

Comment by splante 242 weeks and 4 days ago

splante: thank you.

i have also used this one-liner as a simple way to transform tabs to spaces,

e.g., where output from a program wraps on the terminal solely because it uses tabs, making it more difficult to read.

fstat | se pattern

if we quote the "$a" variable then of course we'll get the tabs.

but in other situations quoting "$a" is useful. e.g. to prevent the shell from expanding certain characters. imagine if some program is listening on an internet socket, and you do

netstat | se LIS

you might not like what you get for the output, unless you have put quotes around "$a".

it seems this website might also benefit from some added attention to shell quoting: i can only see one space between a and b in your example.

Comment by argv 242 weeks and 4 days ago

Your point of view

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