[C/C ++ school] 0801-redirection and file scanning/binary encryption/Decryption/simple encryption/password-based encryption/dynamic library and static library

[C/C ++ school] 0801-redirection and file scanning/binary encryption/Decryption/simple encryption/password-based encryption/dynamic library and static library
Redirection and file scanning

 

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
Void main1 () {char str [100] = {0}; scanf (% s, str); printf (str = % s, str); system (str );} void main2 () {char str [100] = {0}; fscanf (stdin, % s, str); fprintf (stdout, str = % s, str ); system (str);} void main3 () {char * path = C: \ Users \ wuyq \ Desktop \ newcmd.txt; int num = 0; char docmd [30] = {0}; scanf (% d % s, & num, docmd); // accept the keyboard input FILE * pf; pf = fopen (path, w); // write if (pf = NULL) {printf (File opening failed);} else {fprintf (pf, for/l % I in (, % d) do % s, num, docmd); fclose (pf) ;}system (pause) ;}void main4 () {char cmd [100] ={ 0 }; int num = 0; char docmd [30] = {0}; char * path = C: \ Users \ wuyq \ Desktop \ new0000.txt; FILE * pf = fopen (path, r); // read if (pf = NULL) {printf (File opening failed); return;} else {fscanf (pf, for/l % I in, % d) do % s, & num, docmd); printf (num = % d, docmd = % s, num, docmd);} system (pause );} void main () {int num; scanf (num = % d, & num); // The printf (num = % d, num); system (pause );}
  
 

 

 

Binary encryption and decryption

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
Int getfilesize (char * path) {FILE * pf = fopen (path, r); if (pf = NULL) {return-1;} else {fseek (pf, 0, SEEK_END); int length = ftell (pf); return length; // get FILE size} void copy (char * oldpath, char * newpath) {FILE * pfr, * pfw; pfr = fopen (oldpath, rb); pfw = fopen (newpath, wb); // write binary mode if (pfr = NULL | pfw = NULL) {fclose (pfr); // close the file fclose (pfw); return;} else {int length = getfilesize (oldpath); char * p = (char *) malloc (length * sizeof (char); // allocates memory and reads the file fread (p, sizeof (char), length, pfr ); // read the binary data to the memory fwrite (p, sizeof (char), length, pfw); // write the binary data to the file fclose (pfr ); // close the FILE fclose (pfw);} void jia (char * oldpath, char * newpath) {FILE * pfr, * pfw; pfr = fopen (oldpath, rb ); pfw = fopen (newpath, wb); // write binary mode if (pfr = NULL | pfw = NULL) {fclose (pfr ); // close the file fclose (pfw); return;} else {int length = getfilesize (oldpath); char * p = (char *) malloc (length * sizeof (char )); // allocate memory and read the file fread (p, sizeof (char), length, pfr); // read the binary data to the memory for (int I = 0; I <length; I ++) {p [I] ^ = 'a'; // or} fwrite (p, sizeof (char), length, pfw ); // write binary data to the FILE fclose (pfr); // close the FILE fclose (pfw);} void jie (char * oldpath, char * newpath) {FILE * pfr, * pfw; pfr = fopen (oldpath, rb); pfw = fopen (newpath, wb); // write binary mode if (pfr = NULL | pfw = NULL) {fclose (pfr); // close the file fclose (pfw); return;} else {int length = getfilesize (oldpath); char * p = (char *) malloc (length * sizeof (char); // allocates memory and reads the file fread (p, sizeof (char), length, pfr ); // read binary data to the memory for (int I = 0; I <length; I ++) {p [I] ^ = 'a'; // decrypt} fwrite (p, sizeof (char), length, pfw); // write binary data to the file fclose (pfr); // close the file fclose (pfw);} void main () {char * oldpath = C: \ Users \ wuyq \ Desktop \ calc.exe; char * newpath = C: \ Users \ wuyq \ Desktop \ calc.exe; char * newjiepath = C: \ Users \ wuyq \ Desktop \ calc.exe; jia (oldpath, newpath); jie (newpath, newjiepath); system (pause );}
  
 

Simple Encryption

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
// 'A'-> 'B' // hello-> ifmmp // textjjia.txt // textjie.txt // encrypt char jiami (char ch) in byte mode) {return ch ^ 123;} char jiemi (char ch) {return ch ^ 123;} void jia (char * path, char * pathjia) {FILE * pfr, * pfw; pfr = fopen (path, r); // read pfw = fopen (pathjia, w); // write if (pfr = NULL | pfw = NULL) {return;} else {while (! Feof (pfr) // to the end of the file 1, is not 0 {char ch = fgetc (pfr); // read the character putchar (ch ); fputc (jiami (ch), pfw); // write an encrypted character} fclose (pfr); fclose (pfw ); // close the FILE} void jie (char * path, char * pathjie) {FILE * pfr, * pfw; pfr = fopen (path, r ); // read pfw = fopen (pathjie, w); // write if (pfr = NULL | pfw = NULL) {return;} else {while (! Feof (pfr) // to the end of the file 1, is not 0 {char ch = fgetc (pfr); // read the character putchar (ch ); fputc (jiemi (ch), pfw); // write an encrypted character} fclose (pfr); fclose (pfw); // close the file} void main () {char * path = C: \ Users \ yincheng01 \ Desktop \ text.txt; char * pathjia = C: \ Users \ yincheng01 \ Desktop \ textjia.txt; char * pathjie = C: \ Users \ yincheng01 \ Desktop \ textjie.txt; jia (path, pathjia); jie (pathjia, pathjie); system (pause);} void main1 () {FILE * pfr; Char * path = C: \ Users \ yincheng01 \ Desktop \ text.txt; pfr = fopen (path, r); if (pfr = NULL) {printf (File opening failed );} else {printf (original data); while (! Feof (pfr) // feof does not return 0 to the end of the file, to return 1 {char ch = fgetc (pfr); // read a character putchar (ch) from the file ); // output character} rewind (pfr); // return to the beginning of the file printf (encrypted data); while (! Feof (pfr) // feof does not return 0 to the end of the file, and returns 1 {char ch = fgetc (pfr ); // read one character from the file: putchar (ch + 1); // output character} fclose (pfr); // close the file} system (pause );}
  
 

Encrypt by password

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
# Include
   
    
// Encrypted, encrypted by password // file // string encrypted char * stringjiami (char * password, char * string); // string decrypted char * stringjiemi (char * password, char * jiastring); void filejiami (char * path, char * pathjia, char * password); void filejiemi (char * pathjia, char * pathjie, char * password );
   
  
 

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
# Include
   
    
// Encrypted, encrypted by password // file // string encrypted char * stringjiami (char * password, char * string); // string decrypted char * stringjiemi (char * password, char * jiastring); void filejiami (char * path, char * pathjia, char * password); void filejiemi (char * pathjia, char * pathjie, char * password ); # include password encryption. h int getfilesize (char * path) {FILE * pf = fopen (path, r); if (pf = NULL) {return-1;} else {fseek (pf, 0, SEEK_END); // int lengt at the end of the file H = ftell (pf); return length; // return length} char * stringjiami (char * password, char * string) {int passlength = strlen (password ); // obtain the encrypted length int stringlength = strlen (string); // obtain the string length if (stringlength % passlength = 0) {int ci = stringlength/passlength; // number of cycles for (int I = 0; I <ci; I ++) // number of cycles {for (int j = 0; j <passlength; j ++) // cyclic password {string [passlength * I + j] ^ = password [j]; // unique or encrypted} else {int ci = Stringlength/passlength; // number of cycles for (int I = 0; I <ci; I ++) // number of cycles {for (int j = 0; j <passlength; j ++) // cyclic password {string [passlength * I + j] ^ = password [j]; // unique or encrypted} int lastlength = stringlength % passlength; // The remaining length for (int I = 0; I <lastlength; I ++) {string [passlength * (stringlength/passlength) + I] ^ = password [I] ;}return string ;}// string decryption char * stringjiemi (char * password, char * jiastring) {int Passlength = strlen (password); // obtain the encrypted length int stringlength = strlen (jiastring); // obtain the string length if (stringlength % passlength = 0) {int ci = stringlength/passlength; // number of cycles for (int I = 0; I <ci; I ++) // number of cycles {for (int j = 0; j <passlength; j ++) // cyclic password {jiastring [passlength * I + j] ^ = password [j]; // exclusive or encrypted }}else {int ci = stringlength/passlength; // number of cycles for (int I = 0; I <ci; I ++) // loop count {for (int j = 0; j <passlength; j ++) // cyclic password {jiastring [passlength * I + j] ^ = password [j]; // exclusive or encrypted} int lastlength = stringlength % passlength; // The remaining length for (int I = 0; I <lastlength; I ++) {jiastring [passlength * (stringlength/passlength) + I] ^ = password [I] ;}return jiastring;} void filejiami (char * path, char * pathjia, char * password) {FILE * pfr, * pfw; pfr = fopen (path, r); pfw = fopen (pathjia, w); if (pfr = NULL | pfw = NULL) {fclose (pfr); fclose (pfw); return;} else {int length = getfilesize (path ); // get length 430 // int passlength = strlen (password); // get password 20 char * newstr = (char *) malloc (sizeof (char) * (length + 1); for (int I = 0; I <length; I ++) {char ch = fgetc (pfr ); // obtain the character newstr [I] = ch; // keep saving the character // fputc (newstr [I], pfw ); // write characters one by one} newstr [length] = ''; // the string is processed as ''stringjiami (password, newstr); // The encrypted string For (int I = 0; I <length; I ++) {fputc (newstr [I], pfw); // write characters one by one} fclose (pfr ); fclose (pfw); // close the FILE} void filejiemi (char * pathjia, char * pathjie, char * password) {FILE * pfr, * pfw; pfr = fopen (pathjia, rb); pfw = fopen (pathjie, wb); if (pfr = NULL | pfw = NULL) {fclose (pfr); fclose (pfw); return ;} else {while (! Feof (pfr) {char string [256] = {0}; fgets (string, 256, pfr); stringjiemi (password, string); // encrypted Ah fputs (string, pfw); // write the jie Password File} fclose (pfr); fclose (pfw); // close the file }}
   
  
 

# Define _ CRT_SECURE_NO_WARNINGS // close the security check # include
 
  
# Include
  
   
# Include password encryption. h void main () {char string [50] =; char * password = 123; printf (% s, stringjiami (password, string); printf (% s, stringjiami (password, string); char * path = C: \ Users \ yincheng01 \ Desktop \ text.txt; char * pathjia = C: \ Users \ yincheng01 \ Desktop \ textjia.txt; char * pathjie = C: \ Users \ yincheng01 \ Desktop \ textjie.txt; // printf (% d, getfilesize (path); filejiami (path, pathjia, ABCDE ); filejiami (pathjia, pathjie, ABCDE); system (pause );}
  
 

Dynamic library and static library

Static Library

Lib. h

void msg();int  add(int a, int b);

Lib. c

#include
 
  #include
  
   #include
   
     void msg(){         MessageBoxA(0, 1, 2, 0);} int  add(int a, int b){         return a + b;}
   
  
 

Main. c

# Include
 
  
# Include
  
   
# Define delib. h # pragma comment (lib, static library and dynamic library. lib) // the header file only indicates that lib already has the void main () {printf (% d, add (10, 9); msg ();}
  
 

Dynamic library

Dll. c

# Include
 
  
# Include
  
   
# Include
   
    
// Export function, which can be called when loading _ declspec (dllexport) void msg () {MessageBoxA (0, 1, 2, 0);} // export function, call _ declspec (dllexport) int add (int a, int B) {return a + B ;}
   
  
 

Main. c

# Include
 
  
# Include
  
   
# Include
   
    
Typedef void (* pmsg) (); // simplified function pointer typedef int (* padd) (int a, int B); // simplified function pointer void main () {HMODULE mydll = LoadLibraryA (dynamic library. dll); if (mydll = NULL) {printf (dynamic library loading failed);} else {pmsg pmsg1; // define a function pointer pmsg1 = (pmsg) GetProcAddress (mydll, msg); // obtain the function address if (pmsg1! = NULL) {pmsg1 (); // execution} padd padd1; // define the function pointer padd1 = (padd) GetProcAddress (mydll, add); if (padd1! = NULL) {printf (% d, padd1 (10, 29) ;}} FreeLibrary (mydll); system (pause );}