unable to read data from a text file in c - c

//here's the structure
typedef struct student
{
int rno;
char name[20];
struct subject
{
int scode;
char sname[20];
int mark;
} sub[3];
int total;
float per;
} student;
student s1;
FILE *fp;
int j;
fp = fopen("mystudents.txt", "r");
while (fread(&s1, sizeof(student), 1, fp))
{
printf("\n%d \n%s", s1.rno, s1.name);
for (j = 0; j < 3; j++)
{
printf("\n%d", s1.sub[j].mark);
}
printf("\n%d", s1.total);
}
fclose(fp);
Content of my file :
101 brian 23 45 56 124
102 abhi 32 78 90 200

fread() is for reading binary files, not text files (unless you're reading into a string variable). You can use fscanf() to parse the text file.
student s1;
FILE *fp;
fp = fopen("mystudents.txt", "r");
while (fscanf(fp, "%d %s %d %d %d %d", &s1.rno, s1.name, &s1.sub[0].mark, &s1.sub[1].mark, &s1.sub[2].mark, &s1.total) > 0)
{
printf("\n%d \n%s", s1.rno, s1.name);
for (int j = 0; j < 3; j++)
{
printf("\n%d", s1.sub[j].mark);
}
printf("\n%d", s1.total);
}
fclose(fp);

Related

Reading In PPM Pixels As RGB Integers

So my code involves reading in a PPM image and then storing it in an array so it can be saved in an new ppm file. Though I think there is a problem with my pointers that means its not actually reading the file. Also my code ends after allocating the memory for the array. Any help is much appreciated.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxheight 1080
#define maxwidth 1920
#define RGB_COMPONENT_COLOUR 255
#define pgmtype "P2"
#define ppmtype "P3"
typedef struct
{
int red, green, blue;
} PPMPixel;
typedef struct
{
int x, y;
} PPMImage;
typedef struct
{
int rgb_comp_colour;
char filetype[3];
int height;
int width;
} PPMHead;
/*PPMHead head[3];
{
head[3].filetype;
head[3].height;
head[3].width;
}*/
PPMHead head;
PPMHead* head_ptr = &head;
PPMPixel p;
PPMPixel* p_ptr = &p;
PPMPixel *data; //Defines pointer to PPMPixel
int **Array; //Double pointer defines as a pointer pointing to a pointer that is pointing to an integer
PPMPixel **RGBArray; //Double pointer defines as a pointer pointing to a pointer that is pointing to the PPMPixel structure
FILE *fp;
int r, g, b;
void headercheck ()
{
fscanf(fp, "%s %d %d %d", head.filetype, &head.width, &head.height, &head.rgb_comp_colour);
printf("%s %d %d %d", head.filetype, head.width, head.height, head.rgb_comp_colour);
if (head.width > maxwidth || head.height > maxheight)
{
printf("\tInvalid image size. The maximum value of image is 1920x1080.\n");
printf("\tImage size is %d x %d\n", head.width, head.height);
}
else
{
printf("\tImage size is valid\n");
printf("\tImage size is %d x %d\n", head.width, head.height);
}
if ((strcmp (head.filetype, pgmtype)!=0) && (strcmp (head.filetype, ppmtype)!=0))
{
printf("\tInvalid filetype\n");
}
else
{
if(strcmp (head.filetype, pgmtype)==0)
{
printf("\t File is PGM type image\n");
}
else
{
if(strcmp (head.filetype, ppmtype)==0)
{
printf("\t File is PPM type image\n");
}
}
}
if ((head.rgb_comp_colour == RGB_COMPONENT_COLOUR))
{
printf("\t Image is 8 bit\n");
}
else
{
if (head.rgb_comp_colour > RGB_COMPONENT_COLOUR)
{
printf("Maximum bit-depth is 8 bits\n");
}
else
{
printf("\tImage is not 8 bit\n");
}
}
}
int main(void)
{
char fname[100];
printf("Enter file name: ");
scanf("%s", fname);
fseek(stdin,0,SEEK_END);
fp = fopen(fname, "r");
if (fp == NULL)
{
printf("\tError while opening the file\n");
}
else
{
printf("\tReading in %s\n", fname);
}
headercheck();
if (strcmp (head.filetype, ppmtype)==0)
{
RGBArray = (PPMPixel **)malloc(head.height*sizeof(PPMPixel*)); //Points to malloc
if((RGBArray == NULL))
{
printf("Error allocating memory to the array");
}
else
{
printf("Memory allocated to the PPM array sucessfully");
}
for (int i=0;i<head.width;i++)
{
RGBArray[i] = (PPMPixel *)malloc(head.width*sizeof(PPMPixel));
}
printf("Error 2");
//Initialising each element
for (int j=0;j<head.height;j++)
{
for (int i=0;i<head.width;i++)
{
fscanf(fp, "%3d %3d %3d ", &p.red, &p.green, &p.blue); //Scans in integers of the address pointer to PPMPixel
data = &RGBArray[i][j]; //Defines data pointer pointing to address of RGBArray[i][j]
data->red = p.red; //Access member of PPMPixel structure to equal one of the three RGB channels
data->green = p.green;
data->blue = p.blue;
}
}
}
fclose(fp);
//Save PPM Array Into New PPM File
FILE *pf;
int i, j;
char fname2[100];
printf("Enter file name: ");
scanf("%s", fname2);
fseek(stdin,0,SEEK_END);
pf = fopen(fname2, "w");
if (pf == NULL)
{
printf("\tError while opening the file\n");
}
else
{
printf("\tWriting in %s\n", fname2);
}
for(j=0;j<head.height;j++)
{
fprintf(pf, "\n");
for(i=0;i<head.width;i++)
{
fprintf(pf, "%3d ", RGBArray[i][j].red);
fprintf(pf, "%3d ", RGBArray[i][j].green);
fprintf(pf, "%3d ", RGBArray[i][j].blue);
//fprintf(pf, "%3d ", (RGBArray+j*head.width + i)*r);
//fprintf(pf, "%3d ", (RGBArray+j*head.width + i)*g);
//fprintf(pf, "%3d ", (RGBArray+j*head.width + i)*b);
}
}
fclose(pf);
free(RGBArray);
RGBArray = NULL;
for(int i=0;i<head.width;i++)
{
free(RGBArray[i]);
RGBArray[i] = NULL;
}
return 0;
}
You mainly mixed width and height, but there are other issues.
width is the number of columns
height is the number of rows
The C two dimensional array in memory order is Row Major.
The convention for storing an image in memory is "by rows".
The indexing is RGBArray[col][row] (in your code it should be RGBArray[j][i]).
Illustration:
RGBArray[0][0] RGBArray[0][14]
| |
V V
<--- width --->
RGBArray[0] -> ############### ^
RGBArray[1] -> ############### |
RGBArray[2] -> ############### height
RGBArray[3] -> ############### |
RGBArray[4] -> ############### V
I used the following PPM text file for testing (in.ppm):
P3
# ppm comment
4 3
255
1 2 3 11 12 13 21 22 23 31 32 33
101 102 103 111 112 113 121 122 123 131 132 133
201 202 203 211 212 213 221 222 223 231 232 233
Corrected code (please read the comments):
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxheight 1080
#define maxwidth 1920
#define RGB_COMPONENT_COLOUR 255
#define pgmtype "P2"
#define ppmtype "P3"
typedef struct
{
int red, green, blue;
} PPMPixel;
typedef struct
{
int x, y;
} PPMImage;
typedef struct
{
int rgb_comp_colour;
char filetype[3];
int height;
int width;
} PPMHead;
PPMHead head;
PPMHead* head_ptr = &head;
PPMPixel p;
PPMPixel* p_ptr = &p;
PPMPixel *data; //Defines pointer to PPMPixel
int **Array; //Double pointer defines as a pointer pointing to a pointer that is pointing to an integer
PPMPixel **RGBArray; //Double pointer defines as a pointer pointing to a pointer that is pointing to the PPMPixel structure
FILE *fp;
int r, g, b;
void headercheck()
{
char tmp[201]; //Temporary string.
fscanf(fp, "%2s", head.filetype); //%2s ensures that no more than two characters are read.
fscanf(fp, "%200s", tmp);
if (tmp[0] == '#')
{
//The second line may be a comment starting with '#'
fgets(tmp, 200, fp); //Skip the comment.
fscanf(fp, "%d", &head.width);
}
else
{
//If not a comment, read width from tmp.
sscanf(tmp, "%d", &head.width);
}
//fscanf(fp, "%s %d %d %d", head.filetype, &head.width, &head.height, &head.rgb_comp_colour);
fscanf(fp, "%d %d", &head.height, &head.rgb_comp_colour);
printf("%s %d %d %d", head.filetype, head.width, head.height, head.rgb_comp_colour);
if (head.width > maxwidth || head.height > maxheight)
{
printf("\tInvalid image size. The maximum value of image is 1920x1080.\n");
printf("\tImage size is %d x %d\n", head.width, head.height);
}
else
{
printf("\tImage size is valid\n");
printf("\tImage size is %d x %d\n", head.width, head.height);
}
if ((strcmp(head.filetype, pgmtype) != 0) && (strcmp(head.filetype, ppmtype) != 0))
{
printf("\tInvalid filetype\n");
}
else
{
if (strcmp(head.filetype, pgmtype) == 0)
{
printf("\t File is PGM type image\n");
}
else
{
if (strcmp(head.filetype, ppmtype) == 0)
{
printf("\t File is PPM type image\n");
}
}
}
if ((head.rgb_comp_colour == RGB_COMPONENT_COLOUR))
{
printf("\t Image is 8 bit\n");
}
else
{
if (head.rgb_comp_colour > RGB_COMPONENT_COLOUR)
{
printf("Maximum bit-depth is 8 bits\n");
}
else
{
printf("\tImage is not 8 bit\n");
}
}
}
int main(void)
{
const char *fname = "in.ppm";
//char fname[100];
//printf("Enter file name: ");
//scanf("%s", fname);
//fseek(stdin, 0, SEEK_END);
fp = fopen(fname, "r");
if (fp == NULL)
{
printf("\tError while opening the file\n");
}
else
{
printf("\tReading in %s\n", fname);
}
headercheck();
if (strcmp(head.filetype, ppmtype) == 0)
{
RGBArray = (PPMPixel **)malloc(head.height * sizeof(PPMPixel*)); //Points to malloc
if ((RGBArray == NULL))
{
printf("Error allocating memory to the array\n");
}
else
{
printf("Memory allocated to the PPM array successfully\n");
}
//for (int i = 0; i < head.width; i++)
for (int i = 0; i < head.height; i++) //Iterate height rows
{
RGBArray[i] = (PPMPixel *)malloc(head.width * sizeof(PPMPixel));
if ((RGBArray[i] == NULL))
{
printf("Error allocating memory to the array\n");
}
}
//printf("Error 2");
//Initializing each element
for (int j = 0; j < head.height; j++)
{
for (int i = 0; i < head.width; i++)
{
fscanf(fp, "%3d %3d %3d ", &p.red, &p.green, &p.blue); //Scans in integers of the address pointer to PPMPixel
//data = &RGBArray[i][j]; //Defines data pointer pointing to address of RGBArray[i][j]
data = &RGBArray[j][i]; //The row index comes first - (use [j][i] instead of [i][j])
data->red = p.red; //Access member of PPMPixel structure to equal one of the three RGB channels
data->green = p.green;
data->blue = p.blue;
}
}
}
fclose(fp);
//Save PPM Array Into New PPM File
FILE *pf;
int i, j;
//char fname2[100];
//printf("Enter file name: ");
//scanf("%s", fname2);
//fseek(stdin, 0, SEEK_END);
const char *fname2 = "out.ppm";
pf = fopen(fname2, "w");
if (pf == NULL)
{
printf("\tError while opening the file\n");
}
else
{
printf("\tWriting in %s\n", fname2);
}
//Write the PPM header
////////////////////////////////////////////////////////////////////////////
fprintf(fp, "%s\n", head.filetype);
fprintf(fp, "%d %d\n", head.width, head.height);
fprintf(fp, "%d\n", head.rgb_comp_colour);
////////////////////////////////////////////////////////////////////////////
for (j = 0; j < head.height; j++)
{
//fprintf(pf, "\n");
for (i = 0; i < head.width; i++)
{
//fprintf(pf, "%3d ", RGBArray[i][j].red);
//fprintf(pf, "%3d ", RGBArray[i][j].green);
//fprintf(pf, "%3d ", RGBArray[i][j].blue);
fprintf(pf, "%3d ", RGBArray[j][i].red); //row index comes first - use [j][i] instead of [i][j]
fprintf(pf, "%3d ", RGBArray[j][i].green);
fprintf(pf, "%3d ", RGBArray[j][i].blue);
}
fprintf(pf, "\n");
}
fclose(pf);
//free(RGBArray);
//RGBArray = NULL;
for (int i = 0; i < head.height; i++)
{
free(RGBArray[i]);
RGBArray[i] = NULL;
}
free(RGBArray); //Free RGBArray after free RGBArray[i]
RGBArray = NULL;
return 0;
}
Output file (out.ppm):
P3
4 3
255
1 2 3 11 12 13 21 22 23 31 32 33
101 102 103 111 112 113 121 122 123 131 132 133
201 202 203 211 212 213 221 222 223 231 232 233

C Problems with fscanf

Thanks for all the answers, after the corrections the code did not work for a stupid error ... I opened both files with the same file pointer "database" ...
I've read dozens of questions like this but I can't get out of it, I'm going crazy.
The exercise that I have to do asks me to organize the items of a list in a file .txt that has elements of the type: Name Surname Age Wage, in alphabetical order according to the surname.
I have already created a function to insert the elements into the file and it works well.
I then went to the function to organize them but the process stops after the fscanf, and putting some test printf I saw that no values are assigned to the strings or that are assigned absurd numbers.
Please help ... thanks.
This is the code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#define MAX 64
#define MAXFILE 100
void insert();
int fullcheck();
void sort();
typedef struct {
char name[MAX];
char surname[MAX];
int age;
double wage;
} data;
int main() {
insert();
return EXIT_SUCCESS;
}
void insert() {
char c;
int i;
data tmp;
FILE* database;
if ((fullcheck())>MAXFILE-1)
printf("Errore: database pieno.\n");
else {
database=fopen("database.txt", "a");
printf("Nome: ");
fgets(tmp.name, MAX, stdin);
tmp.name[strlen(tmp.name)-1]='\0';
printf("Cognome: ");
fgets(tmp.surname, MAX, stdin);
tmp.surname[strlen(tmp.surname)-1]='\0';
for (i=0; i<strlen(tmp.surname); i++) {
if (tmp.surname[i]==' ')
tmp.surname[i]='#';
}
printf("Eta': ");
scanf("%d", &tmp.age);
printf("Salario: ");
scanf("%lf", &tmp.wage);
while((c=getchar())!='\n');
fprintf(database, "%s %s %d %.0lf \n", tmp.name, tmp.surname, tmp.age, tmp.wage);
fflush(database); fclose(database);
if ((fullcheck())>1)
sort();
}
}
int fullcheck() {
char c;
int r=0;
FILE* database;
if ((database=fopen("database.txt", "r"))==NULL) {
return 0;
}
else {
while((c=getc(database))!=EOF) {
if(c=='\n')
r++;
}
return r;
}
}
void sort() {
char tmpstr[MAX];
int len=fullcheck(), i, a, b;
data tmp[len];
FILE* database;
FILE* sorted;
database=fopen("database.txt", "r");
database=fopen("sorted.txt", "w");
for (i=0; i<=len; i++) {
fscanf(database, "%s %s %d %lf \n", &tmp[i].name, &tmp[i].surname, &tmp[i].age, &tmp[i].wage);
}
for (a=0 ; a<(len-1); a++) {
for (b=0; b<(len-1); b++) {
if ((tolower(tmp[b].surname[0]))>(tolower(tmp[b+1].surname[0]))) {
strcpy(tmpstr, tmp[b].surname);
strcpy(tmp[b].surname, tmp[b+1].surname);
strcpy(tmp[b+1].surname, tmpstr);
}
}
}
for (a=0; a<(len-1); a++) {
fprintf(sorted, "%s %s %d %.0lf \n", tmp[a].name, tmp[a].surname, tmp[a].age, tmp[a].wage);
}
fflush(database); fclose(database); remove("database.txt");
fflush(sorted); fclose(sorted); rename("sorted.txt", "database.txt");
}
Off by 1
Code attempts to read into len+1 elements of tmp[].
data tmp[len];
for (i=0; i<=len; i++) { // too many
fscanf(database, "%s %s %d %lf \n", &tmp[i].name, &tmp[i].surname, &tmp[i].age, &tmp[i].wage);
}
I saw that no values are assigned to the strings (OP)
Better code would use width limits and test fscanf() result before using the data scanned.
// v---- < not <=
for (i=0; i<len; i++) {
if (fscanf(database, "%63s %63s %d %lf",
&tmp[i].name, &tmp[i].surname, &tmp[i].age, &tmp[i].wage) != 4) {
// ^^^^ test!
break;
}
Even better code would read a line with fgets() into a stirng and then attempt to parse the string.
Off by 2
Code's attempt to find number of lines can be short by 1 if the last line does not end with a '\n'.
Alternative
size_t fullcheck(void) {
FILE* database = fopen("database.txt", "r");
if (database == NULL) {
return 0;
}
int previous = '\n';
int c;
size_t r=0;
while((c=getc(database))!=EOF) {
if (previous == '\n') r++;
previous = c;
}
fclose(database);
return r;
}
Missing fclose()
fullcheck() doesn't close the file after opening it.
int
Use an int to distinguish the typically 257 different returns values of fgetc(). Note when char` is unsinged, OP's code is an infinite loop.
More woes
The loop to print the sorted list is off-by-one, too short. And the sorting itself only looks at the first letter of each name, should use strcmp.
#user3386109
Maybe more?
Make sure to close the file here, before every return:
int fullcheck() {
char c;
int r=0;
FILE* database;
if ((database=fopen("database.txt", "r"))==NULL) {
fclose(database);
return 0;
}
else {
while((c=getc(database))!=EOF) {
if(c=='\n')
r++;
}
fclose(database);
return r;
}
}
And also a little bit fixing in the loop_counters here:
void sort() {
char tmpstr[MAX];
int len=fullcheck(), i, a, b;
data tmp[len];
FILE* database;
FILE* sorted;
database=fopen("database.txt", "r");
sorted=fopen("sorted.txt", "w+");
for (i=0; i<len; i++) {
fscanf(database, "%s %s %d %lf \n", &tmp[i].name, &tmp[i].surname, &tmp[i].age, &tmp[i].wage);
printf("%s", tmp[b+1].surname);
system("pause");
}
for (a=0 ; a<(len); a++) {
for (b=0; b<(len); b++) {
if ((tolower(tmp[b].surname[0]))>(tolower(tmp[b+1].surname[0]))) {
strcpy(tmpstr, tmp[b].surname);
strcpy(tmp[b].surname, tmp[b+1].surname);
strcpy(tmp[b+1].surname, tmpstr);
printf("%s", tmp[b+1].surname);
system("pause");
}
}
}
for (a=0; a<(len); a++) {
fprintf(sorted, "%s %s %d %.0lf \n", tmp[a].name, tmp[a].surname, tmp[a].age, tmp[a].wage);
}
fclose(sorted);
fclose(database);
}

Read file and only get integers and keep going till end

#include <stdio.h>
int getIntegers(char *filename,int a[]);
int main(void) {
/////
FILE *fp;
char file[10] = "random.txt";
fp = fopen(file, "w");
fprintf(fp, "1 2 -34 56 -98 42516547example-34t+56ge-pad12345\n");
fclose(fp);
/////
int i;
int a[100];
int n = getIntegers(file,a);
//Here i want to print out what i got from getIntegers. What it should put out = "1 2 -34 56 -98 42516547 -34 56 12345"
if (n > 0)
{
puts("found numbers:");
for(i = 0;i < n; i++)
{
printf("%d ",a[i]);
}
putchar('\n');
}
return 0;
}
int getIntegers(char *filename, int a[])
{
int c, i;
FILE *fp;
fp = fopen(filename, "r");
//I want what this code does to be done with the commented code under it. This will give "1 2 -34 56 -98 42516547"
while (fscanf(fp,"%d",&i)==1)
{
printf("%d ",i);
}
fclose(fp);
// I want this code to give "1 2 -34 56 -98 42516547 -34 56 12345"
// while ((c = fgetc(fp)) != EOF)
// {
// for(i = 0; i < c;i++)
// {
// fscanf(fp, "%1d", &a[i]);
// }
// }
// return i;
}
I have a file with numbers and words/letters in it. With this code I get the integers untill first letter, but i want to continue until EOF. And then return those numbers and print them out in main. I tried but could not get it to work. What should/could i do to get this working? Or what am I doing wrong.
Multiple issues:
int getIntegers() does not return any value. Code does not save anything in a[]. Array limits not enforced.
Commented code does not check the return value of fscanf().
Code needs to consume 1 character when fscanf() returns 0 and then try again.
When fscanf(fp, "%d", &a[i]) returns 0, it means the input is not numeric and fscanf() did not consume any of the non-numeric input. So read 1 character and try again.
#include <stdio.h>
#define N 100
int getIntegers(char *filename, int a[], int n);
int main(void) {
FILE *fp;
char file[] = "random.txt";
fp = fopen(file, "w");
if (fp == NULL) {
fprintf(stderr, "Unable to open file for writing\n");
return -1;
}
fprintf(fp, "1 2 -34 56 -98 42516547example-34t+56ge-pad12345\n");
fclose(fp);
int a[N];
int i;
int n = getIntegers(file, a, N);
puts("found numbers:");
for (i = 0; i < n; i++) {
printf("%d ", a[i]);
}
putchar('\n');
return 0;
}
int getIntegers(char *filename, int a[], int n) {
int i;
FILE *fp = fopen(filename, "r");
if (fp) {
for (i = 0; i < n; i++) {
int cnt;
do {
cnt = fscanf(fp, "%d", &a[i]);
if (cnt == EOF) { fclose(fp); return i; }
if (cnt == 0) fgetc(fp); // Toss 1 character and try again
} while (cnt != 1);
// printf("%d ", i);
}
fclose(fp);
}
return i;
}
Output
found numbers:1 2 -34 56 -98 42516547 -34 56 12345

fprintf saves wrong data to file

I have an input file a.txt:
1 abc 3
2 efgh 4.5
3 text 3
4 xyz 2
So basically, it has 3 columns, first one is int, second is text, and third is double. I need to read this file by rows (which actually works, I guess), but have some problems with writing only second and third column to another (b.txt) file. fprinft saves something like this:
0.000000
0.000000
0.000000
0.000000
xvæ$ 0.000000
instead of
abc 3
efgh 4.5
text 3
xyz 2
I simply need to save only the second and the third column from a.txt file to b.txt file. Here's my code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct mypair
{
char string[1024];
double number;
} mypair;
void zero_string(char *string, int n)
{
int i;
for(i=0; i<n; i++)
string[i] = '\0';
}
int row(FILE* f, struct mypair *p)
{
int num;
if(!feof(f))
{
if(fscanf(f,"%d %s %lf", &num, p->string, &p->number) == 3)
{
return 0;
}
}
else
{
return 1;
}
}
int main(int argc, char **argv)
{
int n = 5, status = 0, i = 0, j;
struct mypair array[5];
char file_in_name[255];
char file_out_name[255];
FILE *fin;
FILE *fout;
zero_string(file_in_name, 255);
zero_string(file_out_name, 255);
printf("Data file:\n> ");
scanf("%s", file_in_name);
printf("Out file:\n> ");
scanf("%s", file_out_name);
fin = fopen(file_in_name, "r");
fout = fopen(file_out_name, "w");
if( fin == NULL )
{
exit(-1);
}
if( fout == NULL )
{
exit(-1);
}
while(status != 1)
{
status = row(fin, &array[i]);
i ++;
fprintf(fout, "%s %lf\n", array[i].string, array[i].number);
if(i >= n)
break;
}
fclose(fin);
fclose(fout);
for(j=0; j<i; j++)
printf("%s %lf\n", array[i].string, array[i].number);
return 0;
}
I modified the code, now it works, thanks!
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct mypair
{
char string[1024];
double number;
} mypair;
void zero_string(char *string, int n)
{
int i;
for(i=0; i<n; i++)
string[i] = '\0';
}
int row(FILE* f, struct mypair *p)
{
int num;
if(!feof(f))
{
if(fscanf(f,"%d %s %lf", &num, p->string, &p->number) == 3)
{
return 0;
}
}
else
{
return 1;
}
}
int main(int argc, char **argv)
{
int n = 5, status = 0, i = 0, j;
struct mypair array[5];
char file_in_name[255];
char file_out_name[255];
FILE *fin;
FILE *fout;
zero_string(file_in_name, 255);
zero_string(file_out_name, 255);
printf("Data file:\n> ");
scanf("%s", file_in_name);
printf("Out file:\n> ");
scanf("%s", file_out_name);
fin = fopen(file_in_name, "r");
fout = fopen(file_out_name, "w");
if( fin == NULL )
{
exit(-1);
}
if( fout == NULL )
{
exit(-1);
}
printf("\n");
while(status != 1)
{
status = row(fin, &array[i]);
if(i >= n)
break;
else
{
if(status != -1)
fprintf(fout, "%s %lf\n", array[i].string, array[i].number);
}
i ++;
}
fclose(fin);
fclose(fout);
for(j=0; j<i; j++)
printf("%s %lf\n", array[j].string, array[j].number);
return 0;
}
In your bottom loop, you want to index your array by j, not i.

Duplicate Elimination in C

I am trying to do duplicate elimination from clients.txt (which has 7 names and surnames, some of them are repeated). In the end of file it writes the output to output.dat file. I did not get any error during the compiling but when i try to run it, it gives "003.exe stopped working" error. (003.c is C project name)
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct names
{
char name[25];
char surname[25];
};
int main()
{
int i, j;
char a[1] = {""};
struct names name[200];
FILE *file;
FILE *file2;
file = fopen("clients.txt", "r");
if (ferror(file))
{
printf ("File could not be opened");
}
while (fscanf(file, "%s", a) == 2)
{
i = 0;
fscanf(file, "%s %s", name[i].name, name[i].surname);
i++;
}
for (i = 0; i < 200; i++)
{
for (j = 0; j < 200; j++)
{
if (i != j && strcmp(name[i].name, name[j].name) == 0 && strcmp(name[i].surname, name[j].surname) == 0 )
{
strcpy(name[j].name, a);
strcpy(name[j].surname, a);
}
}
}
fclose(file);
file2 = fopen("output.dat", "w");
{
for (i = 0; i < 200; i++)
{
if ( strcmp(name[i].name, "") == 1 )
{
fprintf(file, "%s %s\n", name[i].name, name[i].surname);
}
}
}
fclose(file2);
system("pause");
return 0;
}
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct names {
char name[25];
char surname[25];
};
int isEqual(struct names *a, struct names *b){
return strcmp(a->name, b->name) == 0 && strcmp(a->surname, b->surname)==0;
}
int main(){
int i, j;
struct names name[200], a;
FILE *file;
file = fopen("clients.txt", "r");
if (!file){//ferror can't use to fopen
printf ("File could not be opened");
return -1;
}
i=0;
while (fscanf(file, "%24s %24s", a.name, a.surname) == 2){
int dup = 0;
for(j=0; j < i ;++j){
if(dup=isEqual(&a, &name[j]))
break;
}
if(!dup)//!dup && i<200
name[i++] = a;
}
fclose(file);
file = fopen("output.dat", "w");
for (j = 0; j < i; ++j){
fprintf(file, "%s %s\n", name[j].name, name[j].surname);
}
fclose(file);
system("pause");
return 0;
}

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