the code checks if string is in directory files -the code doesnt find matches..i'm using dirent.h

Question

The code checks if a string is in directory files, I think I have problem with
the my searchFile() function

• argv1 is the folder
• argv2 is the string to search

• argv3 is the result file

          #include "dirent.h"
          #include<stdio.h>
          #include<stdlib.h>
          int searchFile(FILE* File1, char * buffer);
          void saveFile(int flag, char * File1Name, char* logAddress);
  
          int main(int argc, char **argv) {
              int flag = 0;
              DIR* dir;
              FILE* File1;
              char * buffer=0;
              long length;
              char address[1000];
              struct dirent *pDirent;
                  dir = opendir(argv[1]);
                  if (dir == NULL) 
                  {
                      printf("Cannot open directory '%s'\n", argv[1]);
                      flag=1;
                  }
                  //convert the signeture file to string
                  FILE * f = fopen(argv[2], "rb");
                  if (f)
                  {
                      fseek(f, 0, SEEK_END);
                      length = ftell(f);
                      fseek(f, 0, SEEK_SET);
                      buffer = (char*)malloc(length*sizeof(char));
                      if (buffer)
                      {
                          fread(buffer, 1, length, f);
                      }
                      fclose(f);
                  }
  
                  if (buffer)
                  {
                      strcpy(address, argv[1]);
                      while ((pDirent = readdir(dir)) != NULL)
                      {
                          if (pDirent->d_name[0] != '.')
                          {
                              printf("[%s]\n", pDirent->d_name);
                              strcat(address, pDirent->d_name);
                              File1 = fopen(address, "rb");
                              printf("%s.\n", address);
                              if (!File1) printf("PROBLEM.\n");
                              flag = searchFile(File1, buffer);
                              saveFile(flag, pDirent->d_name,argv[3]);
                              strcpy(address, argv[1]); 
                          }
  
                      }
                      closedir(dir);
                  }
                  free(buffer);
              system("PAUSE");
              return (0);
          }
  

Input:the file in the dir , FILE*

The function search if a string is in the file and send the result to save file function

Output:none

            int searchFile(FILE* File1, char * buffer)
            {
                int char1, flag = 0,i=0;
                char temp[1000];

                while ((char1 = fgetc(File1)) != EOF && flag == 0)
                {
                    if (*(buffer + i) == char1)
                    {
                        i++;
                        if (strlen(buffer) == i)//if the whole string is             in the FILE.
                        {
                            flag = 1;
                        }
                    }
                    else
                    {
                        i = 0;

                    }
                }
                fclose(File1);
                return flag;
            }

Input:the file in the dir , FILE* int flag

The function prints the all the files and tells who is infected and who isn't

            void saveFile(int flag, char * File1Name, char *logAddress)
            {
                FILE* File2 = fopen(logAddress, "a+");
                if (File2)
                {
                    fprintf(File2, File1Name);
                    if (flag == 1)
                    {
                        fprintf(File2, "  INFECTED!\n");
                    }
                    else
                    {
                        fprintf(File2, "  not infected\n");
                    }
                }
                fclose(File2);
            }