friedkiwi friedkiwi - 2 months ago 22
C Question

Reading the whole text file into a char array in C

I want to read the contents of a text file into a char array in C. Newlines must be kept.

How do I accomplish this? I've found some C++ solutions on the web, but no C only solution.

Edit: I have the following code now:

void *loadfile(char *file, int *size)
{
FILE *fp;
long lSize;
char *buffer;

fp = fopen ( file , "rb" );
if( !fp ) perror(file),exit(1);

fseek( fp , 0L , SEEK_END);
lSize = ftell( fp );
rewind( fp );

/* allocate memory for entire content */
buffer = calloc( 1, lSize+1 );
if( !buffer ) fclose(fp),fputs("memory alloc fails",stderr),exit(1);

/* copy the file into the buffer */
if( 1!=fread( buffer , lSize, 1 , fp) )
fclose(fp),free(buffer),fputs("entire read fails",stderr),exit(1);

/* do your work here, buffer is a string contains the whole text */
size = (int *)lSize;
fclose(fp);
return buffer;
}


I get one warning: warning: assignment makes pointer from integer without a cast. This is on the line
size = (int)lSize;
. If I run the app, it segfaults.

Update: The above code works now. I located the segfault, and I posted another question. Thanks for the help.

Answer
FILE *fp;
long lSize;
char *buffer;

fp = fopen ( "blah.txt" , "rb" );
if( !fp ) perror("blah.txt"),exit(1);

fseek( fp , 0L , SEEK_END);
lSize = ftell( fp );
rewind( fp );

/* allocate memory for entire content */
buffer = calloc( 1, lSize+1 );
if( !buffer ) fclose(fp),fputs("memory alloc fails",stderr),exit(1);

/* copy the file into the buffer */
if( 1!=fread( buffer , lSize, 1 , fp) )
  fclose(fp),free(buffer),fputs("entire read fails",stderr),exit(1);

/* do your work here, buffer is a string contains the whole text */

fclose(fp);
free(buffer);
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