First, go to the Data.police.uk data downloads page and select the last year of stop and search data for a particular police force. At the time of writing I selected data from June 2016 to May 2017, and made sure I ticked 'stop and search data' at the bottom.
This will download as a zip file. Unzip it - you should now have a folder containing all the CSV files for that period: 12 further folders, each with 3 files in it (outcomes, stop and search, and crimes). So, 36 CSVs total. We want to find those and move them to just one folder so we can then combine them.
To make things easier for yourself, move the folder somewhere you can easily see, like Desktop.
Now, also on the Desktop, create a new folder which will hold the files you find. Call it 'foundfiles'
Now here is the sort of command you are going to type - I'll break it down in a moment as it has a number of different parts:
mv `find ~YOURCOMPUTERNAME/Desktop -name "*street.csv"` ~YOURCOMPUTERNAME/Desktop/foundfiles
The first part is mv: this is the 'move' command. You can read more about that, and the related cp, 'copy' command, here.
When using this command you need to specify what you are moving, and where. For example:
mv myfile.txt myfolder
This will move myfile.txt into the folder called 'myfolder'. Note that the destination folder must exist first - it will not create a new folder.
You can also use wildcards like so:
mv *.txt myfolder
This will move any files ending in '.txt' into that myfolder.
Try this out yourself: create a folder called 'myfolder' and a text file called 'myfile.txt', then use command line to navigate into the same place as that text file (use cd to change directory) and then type one of the commands above.
At a basic level mv is limited in only being able to move files it can see in the current directory. However, we can use another command to solve that problem: find
find does exactly that: find files that match a description. This time you need to specify where you are looking, what it is that you are looking at, and what you are looking for. For example:
find ~YOURCOMPUTERNAME/Desktop -name "*.txt"
Here there are three ingredients after the initial find command:
- A path:
~YOURCOMPUTERNAME/Desktop - A property:
-name - A description:
"*.txt"
The path starts with ~ which means the home directory (you can also use $HOME instead). After that comes the name of your particular computer - it might be 'Brian' or 'My Computer'. And then, after a slash, the directory within that which you want to search.
The property is -name but you could also choose to use -size to search by file size, or iname to conduct a name-based search which is not case sensitive.
The description is *.txt - the * is a wildcard which means 'none or more of any character', so as a whole it means 'none or more of any character, followed by .txt'
Taken together, the three elements mean 'find within the ~YOURCOMPUTERNAME/Desktop path, any files with a name which is none or more of any character, followed by .txt'
This will generate a list within Terminal. But we want to use the results within our find command instead.
To use the results of that find command, we need to put the whole thing within a special character: you can see that character below just before find, and after "*street.csv":
mv `find ~YOURCOMPUTERNAME/Desktop -name "*street.csv"` ~YOURCOMPUTERNAME/Desktop/foundfiles
This is taken by mv to describe the files that need to be moved. The second part, then, just describes where to move it to.
Try that. You should now have 12 CSV files together in that folder.
If you need to do this more than once you can store it in a shell script and run that instead. I've done that here. To run it you would use cd to navigate to the folder containing the file, and then enter:
bash moveandcombinecsv.sh