hi all,
i have a file that its a .dat file ok it contains approximately 300 number values, each number value is either a 2 , 3 or 4 digit number like this..
11 111 1678 1334 1445 1335 1225 72 62 42 54 544 944 9111
and so on a so forth.
Now what i need to do is make my C Program able to find a particular number within that file.
I.e All the numbers that have the 2nd number as 1
Could anyone provide me with the guidance on how to do this
Thanks
JC
You could use fgets to read each lines (assuming there are multiple lines?), then use strchr to find the ' ' (space character, which appears to delimit the numbers), then check the character two ahead to see if it's '1'. Repeat until there's no more numbers.
Since the input sounds like it is tightly formatted, I would recommend using fscanf to read each "number" as text. The %s specifier is whitespace delimited, so it will skip the intervening whitespace. Then checking that the second "digit" is a '1' is trivial.
Code:#include <stdio.h> int main() { static const char filename[] = "file.txt"; FILE *file = fopen(filename, "r"); if ( file != NULL ) { char text[5]; while ( fscanf(file, "%4s", text) == 1 ) { if ( text[1] == '1' ) { puts(text); } } fclose(file); } else { perror(filename); } return 0; } /* file.txt 11 111 1678 1334 1445 1335 1225 72 62 42 54 544 944 9111 9191 */ /* my output 11 111 9111 9191 */
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
