I have a line: Something | Something | Something | Something

I want to use sscanf() to limit the input to " | ".

That "Something" is a string that can include any symbol like ",./@#$ etc."

sscanf(line,"%[^'|'] , %[^'|'] , %[^'|'] , %[^'|']",node->x,node->y,node->z,node->w);
//              ^ - I don't know how to put the delimiters.

CodePudding user response：

" , " will scan for optional white-space, a , and then more optional white-space. This is OP's key problem. It should have been " | " to consume the '|' separator.

"%[^'|']" will scan for characters that are not: ', |. Use "%[^|]" to scan for characters that are not |.

"%[^'|']" lacks a width limit - do not omit a width limit if overflow possible.

sscanf() result deserve checking.

Use "%n" to record the offset of the scan. Useful for detecting extra junk in the string.

Put it all together

struct {
  char x[20];
  char y[18];
  char z[16];
  char w[14];
} node;

int n = 0;
sscanf(line, " [^|] | [^|] | [^|] | [^|]%n",
    node.x, node.y, node.z, node.w, &n);
if (n == 0 || line[n]) {
  fprintf(stderr, "Scan failed for <%s>\n", line);
} else {
  Success(); // Your code here
}

Should line contain a '\n', usually that is not wanted either in node.w.

// sscanf(line, " [^|] | [^|] | [^|] | [^|]%n",
sscanf(line, " [^|] | [^|] | [^|] | [^|\n] %n",

CodePudding user response：

To read a line, use fgets rather than scanf:

#include <stdio.h>
#include <string.h>

int main(void) {
    char *x, *y, *z, *w;
    printf("Enter string: ");
    fflush(stdout);
    char line[100];
    fgets(line, sizeof line, stdin);

    x = strtok(line, "|");
    y = strtok(0, "|");
    z = strtok(0, "|");
    w = strtok(0, "\n");

    printf("x:%s\ny:%s\nz:%s\nw:%s\n", x,y,z,w);
}

Enter string: Something1 | Something2 | Something3 | Something4
x:Something1 
y: Something2 
z: Something3 
w: Something4

Enter string: foo
x:foo

y:(null)
z:(null)
w:(null)