add perl one-liners

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -1476,6 +1476,7 @@ In Firefox's addressbar, you can limit results by typing special characters befo
   * [awk](#tool-awk)
   * [sed](#tool-sed)
   * [grep](#tool-grep)
+  * [perl](#tool-perl)
 
 ##### Tool: [terminal](https://en.wikipedia.org/wiki/Linux_console)
 
@@ -3831,6 +3832,62 @@ grep -- -- filename
 grep "\-\-" filename
 ```
 
+##### Tool: [perl](https://www.perl.org/)
+
+###### Search and replace (in place)
+
+```bash
+perl -i -pe's/SEARCH/REPLACE/' filename
+```
+
+###### Edit of `*.conf` files changing all foo to bar (and backup original)
+
+```bash
+perl -p -i.orig -e 's/\bfoo\b/bar/g' *.conf
+```
+
+###### Prints the first 20 lines from `*.conf` files
+
+```bash
+perl -pe 'exit if $. > 20' *.conf
+```
+
+###### Search lines 10 to 20
+
+```bash
+perl -ne 'print if 10 .. 20' filename
+```
+
+###### Delete first 10 lines (and backup original)
+
+```bash
+perl -i.orig -ne 'print unless 1 .. 10' filename
+```
+
+###### Delete all but lines between foo and bar (and backup original)
+
+```bash
+perl -i.orig -ne 'print unless /^foo$/ .. /^bar$/' filename
+```
+
+###### Reduce multiple blank lines to a single line
+
+```bash
+perl -p -i -00pe0 filename
+```
+
+###### Convert tabs to spaces (1t = 2sp)
+
+```bash
+perl -p -i -e 's/\t/  /g' filename
+```
+
+###### Read input from a file and report number of lines and characters
+
+```bash
+perl -lne '$i++; $in += length($_); END { print "$i lines, $in characters"; }' filename
+```
+
 #### Shell functions &nbsp;[<sup>[TOC]</sup>](#anger-table-of-contents)
 
 ##### Table of Contents