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File manipulation
- Thread starter malladisk
- Start date
Zyrenthian
Programmer
open the file
copy the file into a buffer
use strstr to find the string.
use strncpy to copy the characters up til the found string into a new buffer
write the new buffer to a file
advance your pointer to the buffer n where n + return value of strstr
rinse and repeat
Matt
copy the file into a buffer
use strstr to find the string.
use strncpy to copy the characters up til the found string into a new buffer
write the new buffer to a file
advance your pointer to the buffer n where n + return value of strstr
rinse and repeat
Matt
Another way for doing these with less memory consuming is to use a "backup file" just as follow:
#include<stdio.h>
#include<string.h>
void main()
{
FILE *fp,*fb; // fp : pointer for the original file(file1)
char buffer[25]; // fp : pointer for the backup file(file2)
char *string1 = "the searched string";
char *string2 = "string for replacement";
char c;
int size = 0;
if(( fp = fopen( "file1.txt", "r+" )) == NULL ) // opening the files
printf("ERROR:Unable to open \"file1\"\n"
;
if(( fb = fopen( "file12.txt", "w+" )) == NULL )
printf("ERROR:Unable to open or create \"file2\"\n"
size = strlen( string1 );
while(( fgets( buffer, size + 1, fp ) != NULL )) // search for string1 if found
{ // it is replace by string2 and copied to
if( !stricmp( buffer, string1 )) // the backup file
fputs( string2, fb );
else // otherwise,the original content of file1(the original file1)
fputs( buffer, fb ); // is copied to file12(the backup file1)
}
rewind( fb );
rewind( fp );
while(( c = getc(fb)) != EOF ) // Now,this is for outputing the file
{ // to the screen in order to see if the operation
putc( c, fp ); // has succeed.
putchar(c);
}
printf("\n"
fclose(fp); // closing the files
fclose(fb);
}
#include<stdio.h>
#include<string.h>
void main()
{
FILE *fp,*fb; // fp : pointer for the original file(file1)
char buffer[25]; // fp : pointer for the backup file(file2)
char *string1 = "the searched string";
char *string2 = "string for replacement";
char c;
int size = 0;
if(( fp = fopen( "file1.txt", "r+" )) == NULL ) // opening the files
printf("ERROR:Unable to open \"file1\"\n"
;if(( fb = fopen( "file12.txt", "w+" )) == NULL )
printf("ERROR:Unable to open or create \"file2\"\n"
;size = strlen( string1 );
while(( fgets( buffer, size + 1, fp ) != NULL )) // search for string1 if found
{ // it is replace by string2 and copied to
if( !stricmp( buffer, string1 )) // the backup file
fputs( string2, fb );
else // otherwise,the original content of file1(the original file1)
fputs( buffer, fb ); // is copied to file12(the backup file1)
}
rewind( fb );
rewind( fp );
while(( c = getc(fb)) != EOF ) // Now,this is for outputing the file
{ // to the screen in order to see if the operation
putc( c, fp ); // has succeed.
putchar(c);
}
printf("\n"
;fclose(fp); // closing the files
fclose(fb);
}
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