具有重定向输入输出的MadLib C程序

Question

我正在尝试编写一个C程序，它接受MadLib大纲作为.txt文件。然后，该程序要求用户将一系列短语放入Madlib。这部分我已经完成了。但是，我希望能够将用户输入的MadLib短语插入到前面打开的.txt文件中。然后，我希望允许用户以不同的MadLib文件名保存已完成的.txt。MadLib大纲中放置了关键字，表示用户输入的单词应该放在哪里。(见下文)。

我应该如何用用户输入的短语替换这些占位符？

MadLib大纲.txt文件：

One of the most <adjective> characters in fiction is named
"Tarzan of the <plural-noun>." Tarzan was raised by a/an
<noun> and lives in the <adjective> jungle in the
heart of darkest <place>. He spends most of his time
eating <plural-noun> and swinging from tree to <noun>.
Whenever he gets angry, he beats on his chest and says,
"<funny-noise>!" This is his war cry. Tarzan always dresses in
<adjective> shorts made from the skin of a/an <noun>
and his best friend is a/an <adjective> chimpanzee named
Cheetah. He is supposed to be able to speak to elephants and 
<plural-noun>. In the movies, Tarzan is played by <person's-name>.

Answer 1

这使用fscanf从文件中读取数据。它提示输入每种类型的单词，并将最终文本打印到输出文件中。可以将文件名作为命令行的一部分提供，就像在program inputfile outputfile中那样。如果命令行中没有文件名，则输入文件将使用madlib.txt的默认文件名，输出文件将使用madlib-out.txt。

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

int main( int argc, char *argv[]) {
    FILE *fpIn = NULL;
    FILE *fpOut = NULL;
    char cFileIn[100] = { 0};
    char cFileOut[100] = { 0};
    char cIn[500] = { 0};
    char cType[100] = { 0};
    char cWord[100] = { 0};
    char cCh[2] = { 0};
    char *pDash = NULL;

    if ( argc == 3) { // use command line arguments if present
        strcpy ( cFileIn, argv[1]);
        strcpy ( cFileOut, argv[2]);
    }
    else { // default file names
        strcpy ( cFileIn, "madlib.txt");
        strcpy ( cFileOut, "madlib-out.txt");
    }


    fpIn = fopen ( cFileIn, "r");
    if ( fpIn == NULL) {
        printf ( "could not open input file %s\n", cFileIn);
        return 1; // fopen failed
    }

    fpOut = fopen ( cFileOut, "w");
    if ( fpOut == NULL) {
        fclose ( fpIn); // close the input file
        printf ( "could not open output file %s\n", cFileOut);
        return 1; // fopen failed
    }

    // scan up to 499 characters stopping at <
    while ( fscanf ( fpIn, "%499[^<]", cIn) == 1) {
        // scan one character, should be the <
        if ( ( fscanf ( fpIn, "%1s", cCh)) == 1) {
            if ( cCh[0] == '<') {
                fprintf ( fpOut, "%s", cIn); // print to the output file
                // scan the type of word needed
                if ( ( fscanf ( fpIn, "%99[^>]", cType)) == 1) {
                    if ( ( pDash = strstr ( cType, "-"))) {
                        *pDash = ' '; // remove - if present
                    }
                    // for each type, prompt and scan
                    printf ( "Enter a(n) %s\n", cType);
                    // skip whitespace then scan up to 99 characters stopping at newline
                    scanf ( " %99[^\n]", cWord);
                    fprintf ( fpOut, "%s", cWord); // print to the output file
                }
                if ( ( fscanf ( fpIn, "%1[>]", cCh)) == 1) {
                    ; // scan the >
                }
            }
        }
    }

    fclose ( fpIn); // close files
    fclose ( fpOut);
    return 0;
}

Answer 2

这是一个替代的答案，它只是找到和替换(因为编写一个解析器，不破坏不可靠的输入是困难的)。

它从用户读取值，使用strstr函数在文本中找到相关的标记，并替换用户值(如果标记出现不止一次)。替代办法包括：

1. 把所有东西都保存在标签前。
2. 将标记后面的内容复制到另一个字符串。
3. 插入用户值。
4. 复制另一个字符串的内容。

密码..。

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

#define BUFSIZE 65535
#define MAXSTR 100 

int main(int argc, char ** argv) {

    char string_dict[4][3][MAXSTR]  = 
         { {"What is your name? ", "[name]", ""},
           {"What country do you live in? ", "[country]", ""},
           {"What is your age? ", "[age]", ""},
           {"What is your favourite food?", "[favourite food]", ""} };
    int arr_len = sizeof(string_dict)/sizeof(*string_dict);

    char buf1[BUFSIZE];
    char buf2[BUFSIZE];
    char currtag[MAXSTR];
    char *pos = buf1;
    FILE *fd;
    int i;  

    buf2[0] = '\0';

    fd = fopen("input_file.txt", "r");
    fread(buf1, BUFSIZE-1, 1, fd); 
    fclose(fd);

    for (i = 0; i < arr_len; i++) {
        printf("%s", string_dict[i][0]);
        fgets(string_dict[i][2], MAXSTR, stdin);
        string_dict[i][2][strlen(string_dict[i][2])-1] = '\0';
        while (pos = strstr(buf1, string_dict[i][1])) {
            *pos = '\0';
            strcat(buf2, pos + strlen(string_dict[i][1]));
            strcat(pos, string_dict[i][2]);
            pos += strlen(string_dict[i][2]);
            strcat(pos, buf2);
            pos = buf1; 
            buf2[0] = '\0';
        }

    } 

    fd = fopen("output_file.txt", "w");
    fputs(buf1, fd);
    fclose(fd);
}

这是相当有力的，但肯定不是万无一失的。问:当提示输入名称时，输入字符串[name]会发生什么？而且，您可以很容易地超过输入缓冲区。

input_file.txt看起来像：

My name is [name], and I am [age] years old.  
I live in [country] and my favourite nosh 
is [favourite food].

Answer 3

既然已经有了真正的答案，只需简单地指出，如果您有选择，如果您不使用C，您可以更容易地完成它。Python会使它变得微不足道……

infile = open("input_file.txt", "r")
template = infile.read()
infile.close()

questions = [ ["What is your name? ", "[name]"],
              ["How old are you? ", "[age]"],
              ["Which country are you from? ", "[country]"],
              ["What is your favourite food? ", "[favourite food]" ] ]

for q in questions:
    template = template.replace(q[1], input(q[0]))

outfile = open("output_file.txt", "w")
outfile.write(template)
outfile.close

但也许你别无选择。