How to parse table from txt file in C variables? - c

Question

I have a text file in this format:
#Name #Company #ID
Name1 Brand1 1234
Name2 Brand2 5678
And a struct:
struct MyStruct{
char name[TEXT_LEN];
char company[TEXT_LEN];
char ID[TEXT_LEN];
};
typedef struct MyStruct Data_t;
What I want... is to load the data from text file in appropriate variables. It should ignore first line because those are headers...
This is what I've been trying so far but without success:
int loadDataFromFile(Data_t *items, long len, char *inputFile)
{
FILE *fp;
if ((fp = fopen(inputFile, "r")))
{
for (long i = 0; i < len; i++)
{
/*fscanf(fp, "%s %s %s\n", items[i].name, items[i].company, items[i].ID);*/
//this is commented part was not working part... More about this in EDIT
fscanf(fp, "%s %s %s\n", items[i].name, items[i].company, items[i].ID);
printf("Name: %s", items[i].name); // For first item it prints:
// Name: #Name
}
}
return 0;
}
What is wrong here?
EDIT
I've replaced the code but now it reads first line as well. Is there a way to ignore header of file (first line)?

Answer 1

Try This,
#include <stdio.h>
#define TEXT_LEN 100
typedef struct
{
char name[TEXT_LEN];
char company[TEXT_LEN];
char ID[TEXT_LEN];
}Data_t;
int loadDataFromFile(Data_t *items, long len, char *inputFile) // change len as unsigned
{
FILE *fp;
char ch;
long i;
if ( ( fp = fopen(inputFile, "r") ) )
{
while( ( ch = getc(fp) != '\n') && ch!=EOF ); //To ignore first line
printf("Reading...\n");
for (i = 0; i < len && (fscanf(fp, "%s %s %s", items[i].name, items[i].company, items[i].ID) == 3); i++)
{
printf("\n#Name: %s #Company: %s #ID: %s", items[i].name, items[i].company, items[i].ID);
}
}
else
{
printf("File Error");
return 0;
}
return i;
}
int main()
{
Data_t data[2];
int n;
if(n=loadDataFromFile(data,2,"Txt")) //2 is number of line
{
printf("\n\nReaded !\n");
for(int i=0;i<n;i++)
printf("\n#Name: %s #Company: %s #ID: %s",data[i].name,data[i].company,data[i].ID);
}
return 0;
}
Txt:
#Name #Company #ID
Name1 Brand1 1234
Name2 Brand2 5678
Output:
Reading...
#Name: Name1 #Company: Brand1 #ID: 1234
#Name: Name2 #Company: Brand2 #ID: 5678
Readed !
#Name: Name1 #Company: Brand1 #ID: 1234
#Name: Name2 #Company: Brand2 #ID: 5678
[Done] exited with code=0 in 1.227 seconds

Answer 2

the following proposed code:
cleanly compiles
performs the desired functionality
properly discards the first line of the input file (the column headers)
properly checks for errors
properly checks that the data array is not overflowed
assures the fields in the data array are not overflowed when calling sscanf()
properly assures the input file can be read
and now, the proposed code:
#include <stdio.h>
#include <stdlib.h>
#define TEXT_LEN 21
struct MyStruct
{
char name[TEXT_LEN];
char company[TEXT_LEN];
char ID[TEXT_LEN];
};
typedef struct MyStruct Data_t;
long loadDataFromFile( Data_t *items, long len, char *inputFile )
{
FILE *fp = fopen(inputFile, "r");
if( ! fp )
{
perror( "fopen to read file failed" );
exit( EXIT_FAILURE );
}
// read/discard first line:
char buffer[1024];
if( ! fgets( buffer, sizeof( buffer ), fp ) ) // column header line
{
perror( "fgets failed to read column headers from input file" );
exit( EXIT_FAILURE );
}
long i = 0;
while( i < len && fgets( buffer, sizeof( buffer ), fp ) )
{
if( sscanf(buffer, "%20s %20s %20s", items[i].name, items[i].company, items[i].ID) != 3 )
{
break;
}
printf("Name: %s", items[i].name);
i++;
}
return i;
}

Answer 3

you coult try changin
fscanf(fp, "%s %s %s\n", items[i].name, items[i].company, items[i].ID);
to
fscanf(fp, "%s\t%s\t%s\n", items[i].name, items[i].company, items[i].ID);
and also iterating on the file lines could be done better by using something like this
while (!EOF) {/*Code*/}