Dear Friend,
At the moment I am working part time as a Unix / Linux teacher and also
as an AIX system administrator.
Privately I am using Debian / Ubuntu and I use it while in class, giving
presentations and on the fly examples of statements and so on.
In class I tell the students how grep should be used in a directory
called test. Please find the contents of the directory and some files
below. My example of use is as follows:
martin@laptop:~/test$ grep 'Jantje*' school.txt
Which delivers the desired output:
Jantje
Ik las dat Jantje
Jantje voortaan op tijd op school komt,
Hoogachtend, Jantjes vader, Piet Bel.
So far for the class. In reality, however, in most occasions the
statement will be issued like this (objections are being laughed away):
martin@laptop:~/test$ grep Jantje* school.txt
Delivering this undesired output:
Jantjes:Jantje zag eens pruimen hangen
Jantjes:en Jantje wilde pruimen plukken voor zijn moeder
Jantjes:toen zei Jantjes moeder
Jantjes:pas toch op Jantje!
school.txt:Jantje
school.txt:Ik las dat Jantje
school.txt:Jantje voortaan op tijd op school komt,
school.txt:Hoogachtend, Jantjes vader, Piet Bel.
In trying to give more weight to the argument I pointed the students to
the man page of grep, but it struck me that there is not a single
reference to the need of using quotes in the search pattern. This does
not help.
I checked the AIX man page for grep and they at least give some, not
all, examples of using quotes around the search pattern.
The example given above makes me assume grave errors occur in production
environments, just because users are not lead to use search patterns
right.
It may no be the task of the grep project to provide a man page, but
even then I feel there is an opportunity for improvement here by
providing a basic man page with a couple of good examples. I would be
more than glad to contribute.
Files and Contents of test.
Diectory test:
-rw-r--r-- 1 martin martin 208 May 20 2019 Jantje
-rw-r--r-- 1 martin martin 124 Apr 30 2019 Jantjes
-rw-r--r-- 1 martin martin 242 Jun 27 2019 school.txt
The contents of Jantjes and school.txt are:
file Jantjes:
Jantje zag eens pruimen hangen
en Jantje wilde pruimen plukken voor zijn moeder
toen zei Jantjes moeder
pas toch op Jantje!
file school.txt:
Geachte Heer de Vries,
Jantje
Ik las dat Jantje
weer eens te laat op school kwam.
Ik kan u verzekeren dat wij er alles aan
zullen doen om er voor te zorgen dat
Jantje voortaan op tijd op school komt,
Hoogachtend, Jantjes vader, Piet Bel.
Met vriendelijke groet,
Martin.
LinkedIn: https://www.linkedin.com/in/martinsimons1/
GitHub: https://github.com/Webhuis/CFEngine-Roadshow/tree/master/
Twitter: https://twitter.com/webhuis @Webhuis #TheCFEngineRoadshow
