Inserting text in a file instead of overwriting in c

Question

How can I insert characters in a file using C instead of overwriting? I also want to write in start of file and end of a file. I tried this method but it didn't work out (I can re-position but I cannot insert. The text is overwritten)

I've tried this, but it didn't work:

fword = fopen("wrote.txt", "rb+");
fseek(fword, 0, SEEK_SET);
fscanf(fword, "%c", &l);

There is no way to insert text into a file afaik. You can overwrite existing text or append at the end of the file. To insert things, read the file to memory, do your alterations there and then write everything back. — Unimportant
– Unimportant, Commented Apr 16, 2016 at 13:49

ddz · Accepted Answer · 2016-04-16 13:52:46Z

0

To add text at the end, you can open the file with "a" mode (check the fopen manual). It will write your text to end.

To add text in other positions, you have to read everything after that to memory, write what you want and then write the rest.

answered Apr 16, 2016 at 13:52

ddz

5263 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

fluter · Accepted Answer · 2016-04-16 14:18:08Z

0

Files are abstractions of byte streams, there is no such concept as insert in a byte stream, you can seek into certain place and write data there. The bytes you wrote will lay in the file as an array of bytes, if the writing exceeds the current file size, the file will be extended.

answered Apr 16, 2016 at 14:18

fluter

14k10 gold badges72 silver badges113 bronze badges

Collectives™ on Stack Overflow

Inserting text in a file instead of overwriting in c

2 Answers 2

Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Linked

Related