explain well and step by step plz $.$ also easy code too. Thnak you.

For part $1-$ CSV Processing

A CSV $($or Comma Separated Values$)$ file is a text file where columnar $($field$)$ data is separated by commas. But to handle columns that have commas within them we have to enclose that field within quotation marks $("),$ if the field has quotation marks in it then the entire field should be enclosed in quotation marks and the embedded quotation mark has to be doubled $("").$ All records within a CSV file are separated by a newline. In simple terms, each line of the CSV file represents one record. But, a field may contain a newline. If a field does require a newline the entire field has to be enclosed in quotation marks. So more accurately each record of a CSV file is separated by a non$-$quoted newline.

You will need to implement $4$ functions:

csvopen: Opens a CSV file, reads the first line $($header$),$ and returns a null$-$terminated array of C string pointers $($a vector$),$ each representing a column name. This function should also prepare the file for reading subsequent lines. Return NULL on failure. The caller should NOT free the memory associated with the header.

char $**$ csvopen $($char $*$ filename$)$;

csvnext: Reads the next line from the CSV file opened by csvopen, parses it according to CSV formatting rules $($including handling quoted fields, escaped quotes, and embedded newlines$),$ and returns a null$-$terminated array of strings $($vector$),$ each representing a cell value in the row.

char $**$ csvnext $($void$)$;

csvheader: Returns the header read by csvopen as a null$-$terminated array of strings. This can be called at any time after csvopen to retrieve the header. The caller should NOT free the memory associated with the header.

char $**$ csvheader $($void$)$;

csvclose: Closes the CSV file and frees any memory still associated with managing the file $($including the header. Return $-1$ if an error otherwise return how many data lines had been read

int csvclose $($void$)$;

To test your code run make test this will exercise the $4$ functions with the test program. Note that this is not $100\%$ comprehensive but does cover most cases.

This is what your output should look like when you run make test:

student@student:~CSVThreads$ make test

$./$Bierman$\_$Robert$\_$HW$4\_$csv

Header Column $00$: Name $-$ Last, First

Header Column $01$: Age

Header Column $02$: Favorite Color

Header Column $03$: Comments

Data for line $1$

Field $00$: Bierman, Robert

Field $01$: $943$

Field $02$: Blue

Field $03$: What can I say, this is a large comment

Data for line $2$

Field $00$: Smith, John

Field $01$: $28$

Field $02$: Green

Field $03$: I want to have a multiple

line comment

Data for line $3$

Field $00$: Clark, Dwight "The Catch"

Field $01$: $61$

Field $02$: Red & Gold

Field $03$: $1981$ NFC Championship

CSV Tests Passed

student@student:~$/$CSVThreads$ make test