在 fprintf 中格式化输出

Question

感谢您早些时候的帮助，我能够编写一个程序，从文本文件中的文本生成 SHA 512 和 MD5 哈希值，并将输出哈希值放在一个单独的文本文件中。我对此非常感激。程序如下：

文件名：hashgen.c

#include <stdio.h>
#include <string.h>
#include <crypt.h>
#include <stdlib.h>
#include <time.h>


int main (){

    // Start : Display the time of starting the program
    time_t starttime;
    struct tm * starttimeinfo;

    time ( &starttime );
    starttimeinfo = localtime ( &starttime );
    printf ( "Program Started At: %s", asctime (starttimeinfo) );
        //declaring a file to be selected by user
    FILE *user_file;
    char buf[1000];

    FILE *resultfile;
    resultfile = fopen("mytab2411.txt","w");


    // md5 hash
    char * hash_md5 = "$";
    // sha512 hash
    char * hash_sha = "$";

    //Specify Salt   
    char * salt_1 ="$";     
    char * result;
    char encyption_scheme[20];
    char userfilename[128];

    //Prompt to enter file name
     printf("Enter a file name\n");
     scanf("%123s",userfilename);

    //opening the file  
    user_file=fopen(userfilename,"r"); 
    //Error if file does not exist
    if (!user_file){
        printf("Could not find file: %123s",userfilename);
        printf("Please verify the file path");


        time_t exittime1;
        struct tm *exittimeinfo1;

        time ( &exittime1 );
        exittimeinfo1 = localtime ( &exittime1 );


        printf ( "Program Ended At: %s", asctime (exittimeinfo1) );
            return (EXIT_FAILURE);
            }
        //reading from file
        while (fgets(buf,1000, user_file)!=NULL){

        /* hashing using md5 */

            strcpy(encyption_scheme,hash_md5);
            strcat(encyption_scheme,salt_1);
            result = crypt(buf,encyption_scheme);
            fprintf(resultfile,"%s",buf);
            fprintf(resultfile,"%s",result);

             /* hashing using sha-512 */ 
             strcpy(encyption_scheme,hash_sha);
             strcat(encyption_scheme,salt_1);
             result = crypt(buf,encyption_scheme);
            fprintf(resultfile,"%s",buf);

            fprintf(resultfile,"%s",result);
            }
            //closing file
            fclose(resultfile);
            //display time program ended
            time_t endtime;
            struct tm * endtimeinfo;

            time ( &endtime );
            endtimeinfo = localtime ( &endtime );


            printf ( "Program Ended At: %s", asctime (endtimeinfo) );

}

使用的文本文件包含以下文字：

文件名：Sample.txt

John
Paul
Ringo
George

现在，Sample.txt中单词的哈希值存储在mytab2411.txt中。该文件显示为这样。

文件名：mytab2411.txt

John
$$l1fRKKtYSfJOVyWKw3rFH1John
$s3dCSxRBiVAzeBQR.bJLGdPL6VhH4p7fJu2aiaOLxcS4wLpWifoWNxTtaOQGnIHOZadh5rHhuuOOHEicLCV20Paul
$$.NeC/EbTUibao2by.HNV01Paul
$$qQs5aHFZX/2Iaz4Y1RIihRn./AszpUZnDfld0h5mrWEtAqRJPanIO3cpT3TOOKuFS5hpmLrKAb5MY2mGV2ato1Ringo
$$CfsqYxqUQM5x0o.sjBMjV/Ringo
$$iC4vLpyDb5gAw5b7roT79LxiEd3d4LTyi5ftrWW6mwyYHNHenMiaFav4wLR3Rnmut.gJfMHn.Zy.pki9.0OBb.George
$ij/IqfPsZDlXFUEX7H82/George
$$ixjdlMMt3jg1Yb6x91HpVmV3pc9q5o8xFwejxiIyU9yZAoSsiA6qBRuHYInPyQlP4XkrnhuIyUsryLfgtldO5/

我想用fprintf来保证hash值和原来对应的词对齐在一起。例如：

文件名：mytab2411.txt

John $$l1fRKKtYSfJOVyWKw3rFH1    
John $s3dCSxRBiVAzeBQR.bJLGdPL6VhH4p7fJu2aiaOLxcS4wLpWifoWNxTtaOQGnIHOZadh5rHhuuOOHEicLCV20
Paul $$.NeC/EbTUibao2by.HNV01
Paul $$qQs5aHFZX/2Iaz4Y1RIihRn./AszpUZnDfld0h5mrWEtAqRJPanIO3cpT3TOOKuFS5hpmLrKAb5MY2mGV2ato1

有人可以指导我如何使用 printf 对齐上面看到的文本吗？谢谢。

Answer 1

如果您将换行符添加到格式字符串“%s \n”，如果您希望键对齐，那么会将名称放在该行的开头，您可以使用 \t 作为制表符或添加特定大小到格式字符串

在 fprintf 中格式化输出

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