Differences

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--- fuss:sed [2015/01/09 05:34]
127.0.0.1 external edit
+++ fuss:sed [2017/02/22 18:30] (current)
@@ Line 1: / Line 1: @@
+====== Stripping Comments and Newlines ======
+<code bash>
+cat /etc/squid/squid.conf| sed -e 's/^#.*//g' | sed -e ':r;N;s/\n$//g;br'
+</code>
+First part:
+<code bash>
+sed -e 's/^#.*//g'
+</code>
+strips any line beginning (''^'') with ''#'' and anything that follows after the hash.
+Next part:
+<code bash>
+sed -e ':r;N;s/\n$//g;br'
+</code>
+  - create register ''r'',
+  - put newline (''N'') in register r,
+  - substitute all ending newlines (''\n$'') with nothing ''/''''/'',
+  - repeat with register ''r''.
+====== Insert a Space After Every Character ======
+Using bash:
+<code bash>
+cat test | sed -s 's/\([a-zA-Z0-9]\)/\1 /g'
+</code>
+Note that ''sed'' needs the grouping operators ''('' and '')'' escaped.
+====== Insert a Line at a Given Position ======
+Suppose we have a text file containing the following lines:
+<code>
+number 1
+number 3
+</code>
+and that we want to insert ''number 2'' as the second line between ''number 1'' and ''number 3'', we would issue:
+<code bash>
+sed -i '2inumber 2' file.txt
+</code>
+where the parts of the fragments represent:
+  * ''2'' the line number,
+  * ''i'' for the insert command, and
+  * ''number 2'' the data that has to be inserted.
+which will modify the file in-place such that the contents of the file after the insertion becomes:
+<code>
+number 1
+number 2
+number 3
+</code>
+====== Print all Lines Between Bounds ======
+To print out all the lines between ''5'' and ''10'', issue:
+<code bash>
+sed -n '5,10p' file.txt
+</code>