This is a discussion on char by char within the C Programming forums, part of the General Programming Boards category; Ok what i want to start coding is a program that will open a file for reading.. so that i ...
Ok what i want to start coding is a program that will open a file for reading.. so that i can compare it with the users inputs...
the user will be able to enter upto 256 char's.. but im a bit confused on how to compare the users input with the file, char by char. Can anyone help me out on this please
Only the strong survives.
You can get the users input using fgets. Then just compare the string the user gave one char at a time by keeping an index and moving through the string. You can get the next char from an open file by using fgetc.
- SeanCode:for(int index=0;index<256;index++){ if(fgetc(infile)==UserInput[index]) //Do something }
If cities were built like software is built, the first woodpecker to come along would level civilization.
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Use the strcmp() function to compare the two strings.
Definition: Politics -- Latin, from
poly meaning many and
tics meaning blood sucking parasites
-- Tom Smothers
hey guys.. thanx for the reply.. I have done what you told me to do but i keep getting the WRONG part of my code.. can anyone tell me what im doing wrong?
btw i found this site that maybe usefull to othersCode:int main( ) { int index; int c; char buff[MAX]; char buf[MAX]; char *file = "1.txt"; FILE *fp; if(( fp = fopen( file, "r" )) == NULL ) { printf( "-error: could not find file" ); exit( 1 ); } printf( "Enter numbers:\n" ); fgets( buf, MAX, stdin ); // while(!feof( fp )) // { fgets( buff, MAX, fp ); for( index = 0; index < MAX; index++ ) { if( fgetc( fp ) == buf[index] ) { printf( "%s", buff ); break; }else{ printf( "WRONG\n" ); break; } } //} getchar( ); return 0; }
c functions thought maybe it would be good to share it
Last edited by xlordt; 10-22-2003 at 12:38 AM.
Only the strong survives.
Originally posted by xlordt
hey guys.. thanx for the reply.. I have done what you told me to do but i keep getting the WRONG part of my code.. can anyone tell me what im doing wrong?
btw i found this site that maybe usefull to othersCode:int main( ) { int index; int c; char buff[MAX]; char buf[MAX]; char *file = "1.txt"; FILE *fp; if(( fp = fopen( file, "r" )) == NULL ) { printf( "-error: could not find file" ); exit( 1 ); } printf( "Enter numbers:\n" ); fgets( buf, MAX, stdin ); // while(!feof( fp )) // { This statement reads a line from the input file fgets( buff, MAX, fp ); for( index = 0; index < MAX; index++ ) { This statement reads a character from the input file and compares that character to characters from your string of numbers entered above. What about the line you read just before the for()? I'll bet you want to compare the buffer buff and not fgetc() if( fgetc( fp ) == buf[index] ) { printf( "%s", buff ); break; }else{ printf( "WRONG\n" ); break; } } //} getchar( ); return 0; }
c functions thought maybe it would be good to share it
Definition: Politics -- Latin, from
poly meaning many and
tics meaning blood sucking parasites
-- Tom Smothers
Ok i got it working now..thanx.. mind for one more questions..
what im tring to do.. is once they have inputed the wrong, numbers or letters... i what the programm to show me the letter or number that i have inputed wrong.. is this possialbe?
here is the fix of my code
Please remember.. that im still a newbie hereCode:int main( ) { int index; int c; char buff[MAX]; char buf[MAX]; char *file = "1.txt"; FILE *fp; if(( fp = fopen( file, "r" )) == NULL ) { printf( "-error: could not find file" ); exit( 1 ); } printf( "Enter numbers:\n" ); fgets( buf, MAX, stdin ); fgets( buff, MAX, fp ); for( index = 0; index < MAX; index++ ) { if( buff[index] == buf[index] ) { if(!( strcmp( buf, buff )) == 0 ) { printf( "-error: Could not compare inputs" ); break; }else{ printf( "%s", buff ); break; } }else{ printf( "WRONG\n" ); break; } } getchar( ); return 0; }tring to get up to your level
Only the strong survives.
Suggestion -- Take the strcmp outside the for loop. If the strings compare, you are done. If they don't, then go thru the for() loop.Originally posted by xlordt
Ok i got it working now..
what im tring to do.. is once they have inputed the wrong, numbers or letters... i what the programm to show me the letter or number that i have inputed wrong.. is this possialbe?
here is the fix of my code
Code:int main( ) { int index; int c; char buff[MAX]; char buf[MAX]; char *file = "1.txt"; FILE *fp; if(( fp = fopen( file, "r" )) == NULL ) { printf( "-error: could not find file" ); exit( 1 ); } printf( "Enter numbers:\n" ); fgets( buf, MAX, stdin ); fgets( buff, MAX, fp ); This loop seems to be the loop to check each input character with each file character for( index = 0; index < MAX; index++ ) { .. and is verified by this comparison if( buff[index] == buf[index] ) { Then why, each time thru the loop, after checking each character, you compare the entire string? This comparison is done MAX times. Isn't once enough to compare the whole string? if(!( strcmp( buf, buff )) == 0 ) { printf( "-error: Could not compare inputs" ); break; }else{ printf( "%s", buff ); break; } }else{ printf( "WRONG\n" ); break; } } getchar( ); return 0; }
At the first miscompare, you know exactly how many characters compare because INDEX tells you -- print that many spaces and a special char to point to the error.
Also, why go thru the loop MAX times? Use strlen() to find out the length of one of the strings and use that in the for loop.
And close your file.
Definition: Politics -- Latin, from
poly meaning many and
tics meaning blood sucking parasites
-- Tom Smothers
thanx man.. i will give it a try again soon.. you have been a great help.. right now im having a bad day at work
Only the strong survives.
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