Hi guys and gals,
This program below is part of a program that I will eventually finish in the middle of the week. At the moment all it should do is read from a text file and return the data read to show it's done it successfully. I have written this on the engineering computers at Uni and it works fine, but when I came home to re-run it on my laptop, it does not open the txt file, instead always returning the error message I originally programmed!
This is tres annoying, so any advice or comments on why this is so would be helpful.
Thanks!
Code:/**********************************************************************************/ /* Description: This program will read x and y data values from a given text file */ /* and will calculate and plot the best straight line fit for these data. */ /* Author: Edward King */ /* Group: Yc */ /* Date: 10th March 2006 */ /**********************************************************************************/ #include<stdio.h> #include<math.h> #include<grx20.h> #define MAX_SIZE 128 float x[MAX_SIZE] ; float y[MAX_SIZE] ; int read_data_from_file(void) ; #define NO_FILE -1 int main(int argc, char *argv[]) { int pairs_read ; /******************************************************************************/ /* Function Name: read_data_from_file */ /* Description: This function will read x and y data values from a text file. */ /******************************************************************************/ int read_data_from_file(void) { // OPENS A FILE: int i ; FILE *fp ; char file_name[MAX_SIZE] ; // Character array for the data filename. int data_read ; // Asks the user to enter the name and location of the data file. printf("Please enter location and filename of the datafile: ") ; scanf("%s" , file_name) ; fp = fopen(file_name , "r") ; // Opens the file. if( fp == NULL ) ; // Checks for error in opening file. { printf("\nUnable to open file '%s'.\nCheck directory location and filename are correct.\n" "Please close this program and start again.", file_name) ; return NO_FILE ; // Stops program if there is an error in opening the file. } // READS DATA PAIRS FROM THAT FILE: i = 0; // Initialises data pair count. while ( i < MAX_SIZE ) // Checks that i will fit into the array space. { data_read = fscanf( fp , "%f%f\n" , &x[i] , &y[i]) ; // The above reads reads data from the file. // 2 floating point numbers are read, x and y. // Loop continues while 2 data pairs are read and i < 128. if( data_read != 2) break ; { printf( "%8.3f %8.3f\n" , x[i] , y[i] ) ; // Prints the data for user. i++ ; // Increments the number of pairs read. } } //End loop. fclose(fp) ; // Closes the file. return i ; // Retains the number of pairs read. } // END OF "read_data_from_file" FUNCTION. /***********************************************************************/ /* Function Name: pairs_read */ /* Description: This function will print the number of pairs read from */ /* the function "read_data_from_file" or an error message. */ /***********************************************************************/ pairs_read = read_data_from_file() ; { if( pairs_read < 1 ) { printf("\n\nNO DATA READ\n\n") ; //Defines error message. } else { //Prints number of pairs read. printf("\n\n %d data pairs read from the file \n\n", pairs_read) ; } // End IF statement. } // END OF "pairs_read" FUNCTION. system ("PAUSE"); }
