reading parts of a tab delimited file

Hi,

Could anyone please suggest me a way to read parts from a tab -delimted file i.e. I want to read data of the 3rd and the 5th columns?

if my data is:

1234 \t 2342 \t qwert \t iuy1 \t hgy7
2323 \t 2323 \t fghjj \t sdsds \t dwe3
.
.
.

I want to read :
str A =" qwert"
and
str B = "hg7y"


Thanks,
AK

The usual suspects: fgets + sscanf. A skeleton might be as follows.

Code:

---

#include <stdio.h>

int main(void)
{
  static const char filename[] = "file.txt";
  FILE *file = fopen(filename, "r");
  if ( file != NULL )
  {
      char line[BUFSIZ];
      while ( fgets(line, sizeof line, file) != NULL )
      {
        char s[20];
        if ( sscanf(line, "%*s %*s %19s", s) == 1 )
        {
            puts(s);
        }
      }
  }
  else
  {
      perror(filename);
  }
  return 0;
}

/* my output
qwert
fghjj
*/

---

I'll be obliged if you can explain the sscanf line. how is it handling the two columns? what if there were 3 columns, say 1,3 and 5?

http://web.archive.org/web/200502070...t.html#4.9.6.2

[edit]

Code:

---

#include <stdio.h>

int main(void)
{
  static const char filename[] = "file.txt";
  FILE *file = fopen(filename, "r");
  if ( file != NULL )
  {
      char line[BUFSIZ];
      while ( fgets(line, sizeof line, file) != NULL )
      {
        char one[20], three[22], five[18];
        if ( sscanf(line, "%19s %*s %21s %*s %17s", one, three, five) == 3 )
        {
            printf("one = \"%s\", three = \"%s\", five = \"%s\"\n",
                  one, three, five);
        }
      }
  }
  else
  {
      perror(filename);
  }
  return 0;
}

/* my output
one = "1234", three = "qwert", five = "hgy7"
one = "2323", three = "fghjj", five = "dwe3"
*/

---

got u... u rock... :)

Also, if I've a file which have first 4 lines which I don't want to read, how can I move the pointer to the 5th line to start reading?
Is using 4 fgets a good idea?

AK

Perhaps use fgets in a loop to read (and discard) the number of lines you enter a loop with those that you do care about.

But I think there is some problem with it. I use:

Code:

---



char c[120];

for (i=0;i<4;i++){

fgets (c,120,fp);
puts(c);

}

---

and it puts only the 1st line. Is there any way of flushing c?

(edited) Try fflush(NULL) ... it should flush all open streams.