Edit: strtok() proved successful in solving my issue. Thank you Barmar.
I'm still new to C programming, and I have spent several hours now trying to complete a university assignment. What we are supposed to do is take input from a text file containing the availability of food items, and then output those items based on their availability. In essence, the program is supposed to take the name of the file from user input, read the file, store the information into four predefined string arrays, then output the available food items in the format:
name (category) -- description.
The text file has each line ordered as: category, name, description, and availability. The category, name, description, and availability are separated by '\t' characters, which we are supposed to omit.
The issue that I have been having is that I can't seem to figure out how to get the output to print correctly. When I run the program, the output delivers the following mess:
b'Ham sandwich\x04 (Sandwiches\xec\x9dO\x7f) -- Classic ham sandwich\nCaesar salad\x10 (Salads\xff\xff) -- Chunks of romaine heart lettuce dressed with lemon juice\nWater\x96\x19 (Beverages) -- 16oz bottled water\nBeef tacos\x0f\x9eO\x7f (Mexican food) -- Ground beef in freshly made tortillas\n'
I believe the mess to be one of the predefined strings failing to terminate when I print it, almost certainly because it lacks a '\0' character. I also believe that this problem stems from some issue in the way I take each line of text and place each category, name, description, and availability into their respective array. What the true issue is, and how to solve it, is something that I haven't been able to figure out. I have emailed my professor for help, and they said they would get back to me about, but I have yet to get a response from them.
With all that said, here is my current code for the assignment:
#include <stdio.h>
#include <string.h>
int main(void) {
const int MAX_LINES = 25; //Maximum number of lines in the input text file
const int MAX_STRING_LENGTH = 100; //Maximum number of characters in each column of the input text file
const int MAX_LINE_LENGTH = 200; //Maximum number of characters in each line of the input text file
// Declare 4 string arrays to store the 4 columns from the input text file
char column1[MAX_LINES][MAX_STRING_LENGTH];
char column2[MAX_LINES][MAX_STRING_LENGTH];
char column3[MAX_LINES][MAX_STRING_LENGTH];
char column4[MAX_LINES][MAX_STRING_LENGTH];
//get name of file, then open it
FILE* inputFile;
char fileName[MAX_STRING_LENGTH];
scanf("%s", fileName);
inputFile = fopen(fileName, "r");
//string variable to take in each line
//int variable to keep track of / count each line for the column arrays
char fileLine[MAX_LINE_LENGTH];
int countLine = 0;
//when skipping the '\t' character, remember that there is also a null character
//being skipped over in the array being copied too.
while(!feof(inputFile)){
fgets(fileLine, MAX_LINE_LENGTH, inputFile);
if(feof(inputFile)){ //I have found that if I don't check for end-of-file again,
break; //it would duplicate the last line.
}
int i = 0;
int k = 0;
int tabCount = 0; //tabCount to account for skipping over \t characters
//while loop to take file input and put it in respective columns
while( i < strlen(fileLine) ){
if( fileLine[i] == '\t' ){
k = 0;
i++;
tabCount++;
}
///////////////////////////////////////////////
if( tabCount == 0 ){
column1[countLine][k-tabCount] = fileLine[i];
} else if( tabCount == 1 ){
if( !(k >= 1) ){
k = 1;
}
column2[countLine][k-tabCount] = fileLine[i];
} else if( tabCount == 2 ){
if( !(k >= 2) ){
k = 2;
}
column3[countLine][k-tabCount] = fileLine[i];
} else if( tabCount == 3 ){
if( !(k >= 3) ){
k = 3;
}
column4[countLine][k-tabCount] = fileLine[i];
}
///////////////////////////////////////////////
i++;
k++;
}
countLine++;
}
/* Attempt at adding NULL character to strings */
/////////////////////////////////////////////////
/*for(int i = 0; i < countLine; i++){
if( ( column1[i][strlen(column1[i])]) != '\0'){
column1[i][strlen(column1[i])] = '\0';
}
if( ( column2[i][strlen(column2[i])]) != '\0'){
column2[i][strlen(column2[i])] = '\0';
}
if( ( column3[i][strlen(column3[i])]) != '\0'){
column3[i][strlen(column3[i])] = '\0';
}
}*/
/////////////////////////////////////////////////
/* Second attempt at adding NULL character to strings */
/////////////////////////////////////////////////
/*for(int i = 0; i < countLine; i++){
for(int k = 0; k < strlen(column1[i]); k++){
if(column1[i][k] == '\0'){
column1[i][k] = ' ';
}
}
for(int k = 0; k < strlen(column2[i]); k++){
if(column2[i][k] == '\0'){
column2[i][k] = ' ';
}
}
for(int k = 0; k < strlen(column3[i]); k++){
if(column3[i][k] == '\0'){
column3[i][k] = ' ';
}
}
}*/
/////////////////////////////////////////////////
//output
int b = 0;
while( b < countLine ){
if( strcmp(column4[b], "Available\n") == 0 ){
printf("%s (%s) -- %s\n", column2[b], column1[b], column3[b]);
}
b++;
}
fclose(inputFile);
return 0;
}
This is the initial txt file:
Sandwiches Ham sandwich Classic ham sandwich Available
Sandwiches Chicken salad sandwich Chicken salad sandwich Not available
Sandwiches Cheeseburger Classic cheeseburger Not available
Salads Caesar salad Chunks of romaine heart lettuce dressed with lemon juice Available
Salads Asian salad Mixed greens with ginger dressing, sprinkled with sesame Not available
Beverages Water 16oz bottled water Available
Beverages Coca-Cola 16oz Coca-Cola Not available
Mexican food Chicken tacos Grilled chicken breast in freshly made tortillas Not available
Mexican food Beef tacos Ground beef in freshly made tortillas Available
Vegetarian Avocado sandwich Sliced avocado with fruity spread Not available
I would greatly appreciate any help.
This was my adjusted loop, which solved my problem:
while( fgets(fileLine, MAX_LINE_LENGTH, inputFile) != NULL){
token = strtok(fileLine, delimiter);
strcpy(column1[countLine], token);
token = strtok(NULL, delimiter);
strcpy(column2[countLine], token);
token = strtok(NULL, delimiter);
strcpy(column3[countLine], token);
token = strtok(NULL, delimiter);
strcpy(column4[countLine], token);
if( strcmp(column4[countLine], "Available\n") == 0){
printf("%s (%s) -- %s\n", column2[countLine], column1[countLine], column3[countLine]);
}
countLine++;
}
The delimiter variable is a constant and contains the '\t' character. The token variable is a character pointer. Both were declared before entering the while loop.
For the purposes of the assignment, the four column arrays were kept, instead of being condensed down into a single array as suggested by Craig Estey.