What is the regular expression to insert something?

Question

What is the regular expression to insert something after the second backslash / for example 123/456/789 by using sed

Answer 1

#!/bin/sh
PAT='s/\(^[^/]*\/[^/]*\/\)
/\1foo/'
# Pattern was split so Yahoo
# wouldn't truncate it.
echo $PAT
echo '123/456/789' | sed -e $PAT

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Output of the above shell script (pattern, followed by result):

wolf$ ./test_sed.sh
s/\(^[^/]*\/[^/]*\/\)/\1foo/
123/456/foo789
wolf$

Note that it inserts "foo" after the second slash.

======================
The pattern broken down:
\( # start a group
^ # start of line
[^/]* # any number of non-slashes
\/ # a slash
[^/]* # any number of non-slashes
\/ # a slash
\) # end of group

This matches everything in a line up to the second slash. The replacement string is:
\1 # the above group
foo # whatever text you want to insert

Answer 2

RegEx may well be the comparable as techniques of String, and you ought to technique the text cloth besides earlier you ought to reveal. String words; Scanner sc = new Scanner( words ); StringBuilder sb = new StringBuilder(); int count style = 10; jointly as( words.hasNext() ) { count style -= words.next().length(); if( count style < 0 ) { sb.append( "n" ); count style = 10; } sb.append(words.next()); sb.append(" "); } Doing calculations with regEx is il-counseled.

Answer 3

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