Question

我有一个程序，它从命令行参数中获取任意数量的单词，并将其替换为单词＆＃39; CENSORED＆＃39;。我终于让程序为传入的第一个参数工作了，我无法让程序审查所有参数，只用一个字符串输出。该程序相对于给定的参数单独起作用，并未将它们全部考虑在内。我该如何修改？

如何统一使用/操作多个命令行参数？

我的代码如下。

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

char *replace_str(char *str, char *orig, char *rep, int j, int argc)
{
    static char buffer[4096];
    char *p;

    for ( j = 1; j <= argc; j++ )  
    {

        if(!(p = strstr(str, orig)))  // Check if 'orig' is not in 'str'
        {
            if ( j == argc )    {  return str;  }  // return str once final argument is reached
            else                {  continue;    }  // restart loop with next argument
        }

        strncpy(buffer, str, p-str);  // Copy characters from 'str' start to 'orig' str
        buffer[p-str] = '\0';

        if ( j == argc )        {  return buffer;  }
        else                    {  continue;       }
    }
    sprintf(buffer+(p-str), "%s%s", rep, p+strlen(orig));
}

int main( int argc, char* argv[] )  //argv: list of arguments; array of char pointers //argc: # of arguments.
{   
    long unsigned int c, i = 0, j = 1;

    char str[4096];

    while ( (c = getchar()) != EOF )
    {
        str[i] = c;  // save input string to variable 'str'
        i++;
    }
    puts(replace_str( str, argv[j], "CENSORED", j, argc ) );

    return 0;
}


i.e. 
$ cat Hello.txt 

Hello, I am me.

$ ./replace Hello me < Hello.txt

CENSORED, I am CENSORED.

Answer 1

两个问题，你不能保证以空值终止的str，其次，你没有迭代命令行上的单词来审查每个。在getchar()循环后，请在main中尝试以下内容：

/* null-terminate str */
str[i] = 0;

/* you must check each command line word (i.e. argv[j]) */
for (j = 1; j < argc; j++)
{
    puts(replace_str( str, argv[j], "CENSORED", j, argc ) );
}

注意：会将每个CENSORED字放在一个单独的行上。如评论中所述，将puts（或最好printf）移到循环之外以保持一条线。

修改

我道歉。您有比上述更多的问题。尝试检查修复程序时，很明显，根据命令行中输入bad个单词的顺序，您将继续难以解析单词。

虽然可以执行指针运算来复制/扩展/收缩原始字符串，而不管单词出现在命令行中的顺序，但是简单地将提供的单词分成数组，然后进行比较要容易得多针对原始字符串中每个单词的每个坏词。

使用strtok或strsep可以相对轻松地完成此操作。我汇总了一个显示这种方法的快速示例。（注意：在传递给strtok之前复制字符串，因为它会改变原始字符串）。我相信这是你试图做的事情，但是你却没有能力比较每个单词（因此你使用strstr来测试匹配）。

查看示例，如果您有其他问题，请告诉我。注意：我使用4096定义替换了您的硬编码SMAX，并为命令行中输入的字词提供了单词max WMAX。此外始终初始化您的字符串/缓冲区。它将使您始终能够轻松找到缓冲区中的最后一个字符，并确保缓冲区始终以空值终止。

#include <stdio.h> #include <string.h> #include <stdlib.h> #define SMAX 4096 #define WMAX 50 char *replace_str (char *str, char **bad, char *rep) { static char buffer[SMAX] = {0}; char *p = buffer; char *wp = NULL; unsigned i = 0; unsigned char censored = 0; char *str2 = strdup (str); /* make copy of string for strtok */ char *savp = str2; /* and save start address to free */ if (!(wp = strtok (str2, " "))) /* get first word in string or bail */ { if (savp) free (savp); return str; } while (bad[i]) /* test against each bad word */ { if (strcmp (wp, bad[i++]) == 0) /* if matched, copy rep to buffer */ { memcpy (buffer, rep, strlen (rep)); censored = 1; } } if (!censored) /* if no match, copy original word */ memcpy (buffer, wp, strlen (wp)); while ((wp = strtok (NULL, " "))) /* repeat for each word in str */ { i = 0; censored = 0; memcpy (strchr (buffer, 0), " ", 1); p = strchr (buffer, 0); /* (get address of null-term char) */ while (bad[i]) { if (strcmp (wp, bad[i++]) == 0) { memcpy (p, rep, strlen (rep)); censored = 1; } } if (!censored) memcpy (p, wp, strlen (wp)); } if (savp) free (savp); /* free copy of strtok string */ return buffer; } int main ( int argc, char** argv) { unsigned int i = 0; char str[SMAX] = {0}; char *badwords[WMAX] = {0}; /* array to hold command line words */ for (i = 1; i < argc; i++) /* save command line in array */ badwords[i-1] = strdup (argv[i]); i = 0; /* print out the censored words */ printf ("\nCensor words:"); while (badwords[i]) printf (" %s", badwords[i++]); printf ("\n\n"); printf ("Enter string: "); /* promt to enter string to censor */ if (fgets (str, SMAX-1, stdin) == NULL) { fprintf (stderr, "error: failed to read str from stdin\n"); return 1; } str[strlen (str) - 1] = 0; /* strip linefeed from input str */ /* print out censored string */ printf ("\ncensored str: %s\n\n", replace_str (str, badwords, "CENSORED")); i = 0; /* free all allocated memory */ while (badwords[i]) free (badwords[i++]); return 0; }

使用/输出

./bin/censorw bad realbad Censor words: bad realbad Enter string: It is not nice to say bad or realbad words. censored str: It is not nice to say CENSORED or CENSORED words.

多个命令行参数 - 替换单词

1 个答案: