Forum Moderators: bakedjake
Say I have a file at /home/mysite/babes.txt
babes.txt contains:
Britney Spears
Jessica Simpson
Hilary Duff
How do I run a command to appeand to this text file without creating duplicate entries everytime I run it?
Say I want to add 'Anna Kournikova' to the list.
How can I run a command to appeand to it and even if I run it many times there will not be duplicate entries of Anna?
Take a look at sort, which can do exactly what you want IIRC, and also sed, awk, or perl.
There's prolly a fiendishly clever one-liner to do it, but this should work:
echo 'Anna Kournikova' >> /home/mysite/babes.txt ; cat /home/mysite/babes.txt ¦ sort ¦ uniq > /home/mysite/babes.txt
(replace the ¦ character with a pipe (solid vertical line))
How can I run a command to appeand to it and even if I run it many times there will not be duplicate entries of Anna?
Just don't duplicate "Anna", "Anna Kournikova", the first name, or the first and last names of whatever is being appended? The code would be a little different depending on what exactly it is that you need to do?
I mean don't duplicate anna kournikova.
I don't want a code that just append to the list like if I run a code to append to the list 5 time we are going to have
Britney Spears
Jessica Simpson
Hilary Duff
Anna Kournikova
Anna Kournikova
Anna Kournikova
Anna Kournikova
Anna Kournikova
Probably we can do a delete command first to delete Anna Kounikova if it exist, then we append to it,
This way we will not have too many Anna Kournikova in the list.
Sugarcane, does that code prevents duplicates?
Im going to try it anyway.
What do you think is the best solution guys?
/home/mysite/mysite/babes.txt ¦ sort ¦ uniq > /home/mysite/babes.txt
You can't do this in one line -- it will clobber babes.txt before it finishes reading from it!
You want something like
sort <babes.txt ¦ uniq >temp; mv temp babes.txt
(cat babes.txt; echo 'Anna Kournikova') ¦ sort ¦ uniq > babes.txt
append.sh:
egrep -q "^$1$" babes.txt ¦¦ echo "$1" >> babes.txt
Usage:
append.sh "Anna Kournikova"
You don't need the shell script, but it saves a lot of typing ;)
Sean
I learnt a lot today.
That made me a happy boy!
OK, I will go build up my babes.txt now.
How do I modify the code so that it reads newbabes.txt and append the contents to babes.txt?
egrep -q "^$1$" babes.txt ¦¦ echo "$1" >> babes.txt
The first "babes.txt" is what you're checking, the second is what you're appending to. So, if you wanted to check newbabes.txt and append to babes.txt, you'd have
egrep -q "^$1$" newbabes.txt ¦¦ echo "$1" >> babes.txt
Why you'd need to do that, I'm not sure, your original question wanted the same file, this solution doesn't need an intermediate file.
Sean
That is because if I have like 30 names to add I will just need to type them in a text file and run the linux command to merge them instead of entering the name one by one!
Anyway I will try out this new method!
Thanks!
while read A; do
append $A
done
And then
cat newbabes.txt ¦ merge
Sean
