overwriting a specific line on a text file?

c, file, file-writing, variables

Solution

This only works when the new line has the same size as the old one:

- Open the file in the mode `a+`

- `fseek()` to the start of the file

- Before reading the next line, use `ftell()` to note the start of the line

- Read the line

- If it's the line you want, `fseek()` again with the result from `ftell()` and use `fwrite()` to overwrite it.

If the length of the line changes, you must copy the file.

Problem

how do I go about overwriting a specific line on a text file in c?. I have values in multiple variables that need to be written onto the file.

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