How to correctly use sscanf - arduino

Question

I have to write an Arduino function to look up a number in the phone book. My code doesn't work because of the condition using sscanf. What am I doing wrong?
//read the phone book and put the good value in the string
void Read_ADMIN_PHONE_NUMBER(){
String ADMIN_PHONE_NUMBER;
delay(1000);
sendATcommand("AT+CPBS=\"SM\"", 500) ; //Select the SIM phonebook
sendATcommand("AT+CPBR=1,99", 100) ; // To read ALL phonebook +CPBR: 1,"690506990",129,"ANDROID"---- exemple de reponse copier du serial monitor
if (1 == sscanf(fonaInBuffer, "+CPBR: %*s", &ADMIN_PHONE_NUMBER)) {
Serial.println(F("*****"));
Serial.println(ADMIN_PHONE_NUMBER);
} else {
Serial.println(F("**bad***"));
}
delay(2000);
}
My problem come from the sscanf.I can't put fonaInBuffer in ADMIN_PHONE_NUMBER
void Read_ADMIN_PHONE_NUMBER(){
String ADMIN_PHONE_NUMBER;
delay(1000);
sendATcommand("AT+CPBS=\"SM\"", 500) ; //Select the SIM phonebook
sendATcommand("AT+CPBR=1,99", 100) ; // To read ALL phonebook like example: +CPBR:1,"690506990",129,"ANDROID"
if (1 == sscanf(fonaInBuffer, "+CPBR: %*s", &ADMIN_PHONE_NUMBER)) {
Serial.println(ADMIN_PHONE_NUMBER);
} else {
Serial.println(F("**bad***"));
}
delay(2000);

Answer 1

The * in %*s means 'do not assign', and such conversion specifications are not counted in the number of successful conversions. Therefore, the sscanf() call will return 0 always (unless the scanned string is empty; then it returns EOF) because there is no active conversion.
Remove the *, or replace it with a suitable number. If the ADMIN_PHONE_NUMBER is a char ADMIN_PHONE_NUMBER[123];, then the number you use should be (at most) 122: %122s — because sscanf() writes a null after the 122 characters if it reads 122 characters in a single 'word'. It is not clear what String ADMIN_PHONE_NUMBER; means — more precise advice cannot be given because of that.
Reducing your code to close to an MCVE (How to create a Minimal, Complete, and Verifiable Example?):
#include <stdio.h>
int main(void)
{
char buffer[] = "+CPBR: 1,\"690506990\",129,\"ANDROID\"";
char number[64];
int n = sscanf(buffer, "+CPBR: %63s", number);
printf("n = %d: number = [%s]\n", n, number);
n = sscanf(buffer, "+CPBR: %*d , \" %63[^\"]", number);
printf("n = %d: number = [%s]\n", n, number);
return 0;
}
Sample output:
n = 1: number = [1,"690506990",129,"ANDROID"]
n = 1: number = [690506990]
Take your pick as to which you want to use. I've been liberal with allowed white space in the sscanf conversion specifications. You can be less liberal if you prefer.