将 md5sum 输出复制到 C 程序中的字符串

Question

我正在尝试使用 sprintf 函数将 md5Sum 输出复制到字符串。但是当我打印输出字符串时，它总是显示为零。我在这里犯了什么错误？

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

int main()
{
  char command[50];
  char buffer[50];
  int len;
  puts("Enter the password");
  fgets( buffer, 50, stdin);
  strcpy(command, "echo -n ");
  len = strlen(buffer);
  if (buffer[len - 1] == '\n')
  buffer[len - 1] = '\0';   
  strcat(command, buffer);      
  strcat (command, "| md5sum");
  system(command);
  bzero(buffer, 50);
  sprintf(buffer, "%x", system(command));
  puts(buffer);
  return(0);
  }

输出:

elcot@boss:~$ ./md5sum
Enter the password
Karthi
51ea12796f11f1f4b72fa9316c45ead3  -
51ea12796f11f1f4b72fa9316c45ead3  -
0

Answer 1

您可以尝试“popen”功能:

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

int main()
{
  char command[50];
  char buffer[50];
  int len;
  puts("Enter the password");
  fgets( buffer, 50, stdin);
  strcpy(command, "echo -n ");
  len = strlen(buffer);
  if (buffer[len - 1] == '\n')
  buffer[len - 1] = '\0';   
  strcat(command, buffer);      
  strcat (command, "| md5sum");
  //system(command);
  bzero(buffer, 50);

  FILE *lsofFile_p = popen(command, "r");

  char *line_p = fgets(buffer, sizeof(buffer), lsofFile_p);
  pclose(lsofFile_p);

  printf("%s",buffer);

  return(0);
  }