Add Count The Lines In A CSV Where A Column Is Empty as a Unix TIL

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
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-_1339 TILs and counting..._
+_1340 TILs and counting..._
 
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@@ -1257,6 +1257,7 @@ _1339 TILs and counting..._
 - [Configure cd To Behave Like pushd In Zsh](unix/configure-cd-to-behave-like-pushd-in-zsh.md)
 - [Copying File Contents To System Paste Buffer](unix/copying-file-contents-to-system-paste-buffer.md)
 - [Copying Nested Directories With Ditto](unix/copying-nested-directories-with-ditto.md)
+- [Count The Lines In A CSV Where A Column Is Empty](unix/count-the-lines-in-a-csv-where-a-column-is-empty.md)
 - [Count The Number Of Matches In A Grep](unix/count-the-number-of-matches-in-a-grep.md)
 - [Count The Number Of ripgrep Pattern Matches](unix/count-the-number-of-ripgrep-pattern-matches.md)
 - [Create A File Descriptor with Process Substitution](unix/create-a-file-descriptor-with-process-substitution.md)

unix/count-the-lines-in-a-csv-where-a-column-is-empty.md

@@ -0,0 +1,25 @@
+# Count The Lines In A CSV Where A Column Is Empty
+
+The [`xsv` utility](https://github.com/BurntSushi/xsv) is a fast way to analyze
+and work with CSV files from the command line.
+
+With the `search` subcommand, I can seach for lines that match a pattern and
+even narrow that search to focus on a selected column.
+
+For instance, to search for any lines where column 3 is empty:
+
+```
+$ xsv search -s 3 '^$' data.csv
+```
+
+The `-s 3` narrows the search to just column 3. The `'^$'` regex pattern
+matches on cells where there is the start character (`^`) and end character
+(`$`) with nothing in between, hence empty.
+
+I can then pipe that to `wc -l` to get a count of the number of empty lines.
+
+```
+$ xsv search -s 3 '^$' data.csv | wc -l
+```
+
+See `xsv search --help` for more details.