CODEWITHSUNDEEP
cfile-ioscanf
darksky
darksky

Reputation: 21019

fscanf not scanning file

I am trying to scan a file using fscanf and put the string into an char array of size 20 as follows:

char buf[20];
fscanf(fp, "%s", buf);

The file fp currently contains: 1 + 23.

I am setting a pointer to the first element in buf as follows:

char *p;
p = buf;

Printing buf, printf("%s", buf) yields only 1. Trying to increment p and printing prints out rubbish as well (p++; printf("%c", *p)).

What am I doing wrong with fscanf here? Why isn't it reading the whole string from the file?

Upvotes: 1

Views: 353

Answers (1)

Filip Roséen
Filip Roséen

Reputation: 63797

fscanf (and related functions) with the format-string "%s" will try to read as many characters as it can without including a whitespace, in this case it will find the first character (1) and store it, then it will hit a space () and therefore stop searching.

If you'd like to read the whole line at once consider using fgets, it is also safer to use since you need to specify the size of your destination buffer as one of it's arguments.

fgets will try to read at maximum length-of-buffer minus 1 characters (last byte is saved for the trailing null-byte), it will stop at either reading that many characters, hitting a new-line or the end of the file.

fgets (buf, 20, fp);

Links to documentation

Upvotes: 7

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