Lecture fichier texte

Exemple de création puis de lecture d’un fichier texte délimité par des ;

Remarque la fin de ligne est signalée par les caractères CR et LF soit Aciii 13 puis 10

 /* v2.0  
  This example shows how to read and write structured data to and from an SD card file        
  The circuit (UNO BOARD):  
  * SD card attached to SPI bus as follows:  
  ** MOSI - pin 11  
  ** MISO - pin 12  
  ** CLK - pin 13  
  ** CS - pin 4  
  */  
 #include <SD.h>  
 File fAccess;  
 String sUser[4][3]; //-- Store the 4 User, Password, Profile in a 3 dimentional array  
 int i1,i2;  
 //Parsing des lignes à l'aide : stringOne.indexOf  
 void setup(){  
  Serial.begin(9600);  
  //-- SD initialization  
  pinMode(4, OUTPUT); //-- pin 10 Uno, pin 4 for Ethernet Shield  
  if (!(SD.begin(4))) {  
   Serial.println("initialization rate!");  
   return;  
  }  
  Serial.println("initialization done.");   
   //-- Writing Data (UserName, UserPass, UserProfile)  
   fAccess = SD.open("access.txt", FILE_WRITE);  
   //-- if the file opened okay, write to it:  
   if (fAccess) {  
   Serial.print("Writing access...");  
   fAccess.println("user1;pass1;profil1");  
   fAccess.println("user2;pass2;profil2");  
   fAccess.println("user3;pass3;profil3");  
   fAccess.println("user4;pass4;profil4");    
        // close the file:  
   fAccess.close();  
   Serial.println("done.");  
   } else {  
   // if the file didn't open, print an error:  
   Serial.println("Error writting file");  
   }  
  //-- re-open the file for reading:  
  int i=1;  
  int j=0;  
  String sVar="";  
  char cCar;  
  fAccess = SD.open("access.txt");  
  if (fAccess) {  
   Serial.println("Reading access.txt:");  
   i=1;  
   // read from the file until there's nothing else in it:  
   while (fAccess.available()) {  
    cCar=fAccess.read();  
    Serial.print("-");  
    Serial.print(cCar+0);  
    Serial.print("-");  
    if (cCar!=13)  
      if (cCar!=10)  
       sVar=sVar+cCar;  
    else  
    {  
     Serial.println("");  
     sVar.trim();  
     Serial.println(sVar);  
     i1=sVar.indexOf(';');  
     i2=sVar.indexOf(';',i1+1);  
     Serial.println("User="+sVar.substring(0,i1));  
     Serial.println("Pass="+sVar.substring(i1+1,i2));  
     Serial.println("Profil="+sVar.substring(i2+1));  
     i++;  
     sVar="";  
    }  
   }  
     Serial.println("");  
     sVar.trim();  
     Serial.println(sVar);  
     i1=sVar.indexOf(';');  
     i2=sVar.indexOf(';',i1+1);  
     Serial.println("User="+sVar.substring(0,i1));  
     Serial.println("Pass="+sVar.substring(i1+1,i2));  
     Serial.println("Profil="+sVar.substring(i2+1));  
   // close the file:  
   fAccess.close();  
   fAccess.flush();  
   SD.remove("access.txt");  
   Serial.println("Deleting access.txt");  
  }  
  else {  
   // if the file didn't open, print an error:  
   Serial.println("error opening access.txt");  
  }   
 }  
 void loop()  
 {}  

Ecran de contrôle :
Reading access.txt:

-117–115–101–114–49–59–112–97–115–115–49–59–112–114–111–102–105–108–49–13–10-

user1;pass1;profil1

User=user1

Pass=pass1

Profil=profil1

-117–115–101–114–50–59–112–97–115–115–50–59–112–114–111–102–105–108–50–13–10-

user2;pass2;profil2

User=user2

Pass=pass2

Profil=profil2

-117–115–101–114–51–59–112–97–115–115–51–59–112–114–111–102–105–108–51–13–10-

user3;pass3;profil3

User=user3

Pass=pass3

Profil=profil3

-117–115–101–114–52–59–112–97–115–115–52–59–112–114–111–102–105–108–52-

user4;pass4;profil4

User=user4

Pass=pass4

Profil=profil4