Thread: Adding line numbers to file

I want to write a program in which
1.Number the lines in a file
2.Display n lines from a given line number.
3. Delete a particular line
4. Search for a given word and print all the lines where the word is found
i want to know what will be basic idea behind it after opening any file??

File I/O is your friend. Sounds like the getline() function will be super handy.

1) Do you mean modify the existing file with line numbers? If so you might want to getline() then 'add' the line number (kept in order with an indexing integer say in a for loop), and then write that back into the file.

2)

Code:

for NUM_LINES_TO_DISPLAY
    getline(temp, 256)
    cout temp

3) Index the lines by 1,2,3,4,5... then scan down to the line you want to delete?

4) Since you can't sort the lines in a file because I'm assuming there is no structure to the data in each line, you'll have to do a linear search.

Code:

for each line
   getline()
   for each word
      if tempword = key
          //the word does reside in this line!

cool, thx.....let me try to write this down

so what will be function for c like getline