CODEWITHSUNDEEP
clinuxstringgccscanf
ericin
ericin

Reputation: 11

C - How to read with sscanf <int><string><int>?

I have a file with <int><string><int> and I save it into a buffer and read it afterwards using a pipe. The string is alphanumeric.

FILE *est = fopen ("file.txt","r");
fgets( buffer1, 256, est);
write(fd[i][1], buffer1, BUFFERSIZE);

.
.
.

int r = read(fd[i][0], buffer1, BUFFERSIZE);
sscanf(buffer1,"<%d><%s><%d>", &a, b, &c);

The problem is when I read the string it "eats" the ><%d> and it interprets everything as a string. For example if I had <10><5jj8j><10> the variables would be a=10, b= "5jj8j"><10> and c to whatever it is initialized.

How can I use sscanf to read the string between <> right?

Thanks for the answers.

Upvotes: 1

Views: 518

Answers (1)

chux
chux

Reputation: 153457

Since "%s" saves all non-white-space characters and OP does not want '>' to be saved as part of the string, use "%[]".

Use "%n" to detect if scan completed as n, being at the end, will only change if all the format matched.

// sscanf(buffer1,"<%d><%s><%d>", &a, b, &c);
int n = 0;
char b[100];
sscanf(buffer1,"<%d><%99[^>]><%d>%n", &a, b, &c, &n);
if (n > 0) {
  ; // Scan completed - success;
} else {
  ; // Scan failed
}

Upvotes: 1

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