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write to a file

Posted on 2002-04-29
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Last Modified: 2010-04-15
Hi,
   How can I write a couple of lines to a file using c?
ex:  I want a simple c program which will write three lines to a file call
/tmp/file1 under solaris.

after I run the c program, it should write the three lines to the /tmp/file1

/tmp/file1 contains:
#! is line one
line2
line3 is good

thanks in advance
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Question by:siunix
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5 Comments
 
LVL 6

Expert Comment

by:kotan
ID: 6979424
FILE *fptr;

fptr = fopen("w", "/tmp/file1");

fprintf(fptr, "#! is line one");
fprintf(fptr, "line2");
fprintf(fptr, "line3 is good");

fclose(fptr);
0
 
LVL 1

Expert Comment

by:Shivshankar
ID: 6979426
void g()
{
  FILE * f;
  f = fopen("/tmp/file1", "w");
  //Code for writing into the file
  //goes here...
  fclose(f);
}
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LVL 1

Accepted Solution

by:
tapasmondal earned 200 total points
ID: 6979458
There are two options:
1. You want to creat a new file which having only these threee lines.
2. You want to add these threee lines in a existing file.


for 1. you will have to open this file in write mode.
like as follow:

void file_to_write()
{
FILE *fin;
fin = fopen("/tmp/file1","w");
fprintf(fin, "#! is line one");
fprintf(fin, "line2");
fprintf(fin, "line3 is good");

fclose(fin);
}

for 2. you will have to open this file in append mode.
like as follow:

void file_to_write()
{
FILE *fin;
fin = fopen("/tmp/file1","a");
fprintf(fin, "#! is line one");
fprintf(fin, "line2");
fprintf(fin, "line3 is good");

fclose(fin);
}



If you want to creat in binary mode, you have to replace "w" by "wb" and "a" by "ab".

Thanking you

tapas

0
 

Author Comment

by:siunix
ID: 6979540
great answer.
thanks for all your help.
0
 

Author Comment

by:siunix
ID: 6982251
I try:
fprintf(fptr, "fi");

and it does not write "fi" to the file.
is there a fix for this?


thanks


0

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