hiho@ll

what is the best way to insert something in the middle of a file using ansi c functions?

it's not really a problem i have, but i just wanted to know the answer, because:
1. FILE *fp=fopen("test.file","a");
fseek(fp,ftell(fp)/2,SEEK_SET);
fprintf(fp,"TEST");

appends TEST at the end of the file (well, it does what it should do)

2. using fopen("test.file","w");
it replaces the text

so, how can i just insert a text using ansi c?
btw: how can this be done in c++?

thx@ll

I think there is no direct function is available which insert a string in middle of file.

Just try it


Open your first file.

Create a new temporary file
write the first part of first file to temporary file (from where you hv to insert the string)

Then write your string to temporary file

then write the rest of the first file to temporary file.

Delete the first file
Rename the temporary file to first file


Or second mathod

Seek to the position where u have to write string.

Copy the rest of the file to another file or memory

append the string at the point you are at.

append the saved piece of file which u saved earlier to memory or temporary file.


Hope it will solve

You could open a second file, dump the contents of the first file upto the point where you wish to insert the new contents. Then insert the new contents and then write the rest of the file.

that's what i thought, but i hoped that there is a function which will do the work
because this methods are really unsave i think

thx@ll

no, there is nothing unsafe about them.

Nothing unsafe in this practice almost every programmer is doing this frequently and found nothing going wrong. Just confidence needed.