Split a string by a given delimiter

 I was really amazed to find out that C++ string class has no split method. There are plenty of accasions I needed to split a string by a given delimiter. Lets see how to split a string and put substrings in a to vector. 

If you think incrementing varable start is ugly, you can use function find_first_not_of for it

Handle circular dependancy in c++

 This SOF question contains all. :) No need to write it agian.

modify files using sed in linux

 sed is a powerfull tool and you can find all details from here

delete a line containing a substring ("pattern")

sed -i '/pattern/d' file

replace a string

sed -e s/pattern//g -i file

using i.backup will keep a backup file of original and it is safer.  

sed -e "s/pattern//g" -i.backup file

Get parent directory name of shell script

 pwd | rev | cut -d/ -f1 | rev

lets see arguments for cut used with above command

spliting delimeter is given to -d, in this case \

required argument is given to -f, in this case 1

rev is used to reverse the string because parent directory name is the first argumet from reverse of pwd.

Get substring of a string in shell

 I wanted to get a only file names from the output of  command find . -maxdepth 1 -type d

This returns a strings contains "./" at the begining.

./1-case

./2-case

./3-case

./4-case

./5-case

./6-case

to remove first two characters i used command cut. as follows

echo "./1-case" | cut -c3-

-c means return characters

3- means from 3rd character to end

other examples

-c3 will return only 3rd character

-c3-4 will return characters form 3rd to 4th

 

Get the all folder names in current directory

 I wanted to copy a file from one location to multiple folders. We'll have to copy multiple times if we do it manally. Lets see how to use shell script to copy to every folder in one go using shell scripting.

main parts we need to do.

1. get all directories.

    find . -maxdepth 1 -type d

2. loop through every directory name, returned from 1, and copy file to each folder.

using foreach loop in s shell (.csh) 

> foreach dir ( ` find . -maxdepth 1 -type d` )
> foreach? cp ~/Scripts/convert.py $dir
> foreach? end

using for loop in bash shell (.sh)

Other commands to get all directory names

1. ls -d */
2. ls -l | grep `^d'

Overview of TDD and BDD

I wanted to know what are the differences between Test Driven Development and Behaviour Driven Development. So I went through many youtube videos and found following videos useful. 

Test Driven Development

Behaviour Diven Divelopment