文本文件中的C字符串

Question

我是C編程語言的新手。 如何從文本文件中搜索特定字符串並將其放入數組，然后從這些數組生成單個字符串？

文本文件：

name1,name2,name3,type1,g1,g2,g3
name1,last1,last2,type2,g4,g6,g7
foo1,foo2,foo3,type3,gx,g3,g5
foo1,doo1,doo2,type4,g1,gt,gl

輸出應該在1個字符串中，而不是分開，所以如果說它是

printf("%s", strings);

它給出如下輸出：

2 records found

Name: name1,name2,name3
type: type1
g1 type: g1
g2 type: g2
g3 type: g3

Name: name1,last1,last2
type: type2
g1 type: g4
g2 type: g6
g3 type: g7

到目前為止，我的嘗試是獲取文本文件並搜索字符串：

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

int main(){


    char tmp[1000];
    int count=0;

    FILE *fp=fopen("test.csv","r");

    while(fgets(tmp, sizeof(tmp),fp) != NULL){
            if (strstr(tmp, "name1")){
                    count = count + 1;
                    printf("%s", tmp);
            }
    }

}

僅給出輸出：

name1,name2,name3,type1,g1,g2,g3
name1,last1,last2,type2,g4,g6,g7

嘗試中：

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

int main(){


    char tmp[1000];
    int count=0;
    char *string;
    char *name1, *name2, *name3, *type,*g1,*g2,*g3;

    FILE *fp=fopen("test.csv","r");

            while(fgets(tmp, sizeof(tmp),fp) != NULL){        

                    name1 = strtok(tmp,",");
                    name2 = strtok(NULL,",");
                    name3 = strtok(NULL,",");
                    type= strtok(NULL,",");
                    g1= strtok(NULL,",");
                    g2= strtok(NULL,",");
                    g3= strtok(NULL,",");

                    if (strstr(tmp, "name1")){
                            count = count + 1;
                            string = malloc(sizeof(*string));
                            sprintf(string, "\n%d record(s) found.\n\nName: %s, %s, %s \nType: %s\ng1 type: %s\ng2 type: %s\ng3 type: %s", count, name1, name2,name3,type,g1,g2,g3);
                    }
        }
        printf("%s", string);

}

輸出：

2 record(s) found.

Name: name1, last1, last2 
Type: type2
g1 type: g4
g2 type: g6
g3 type: g7

Answer 1

首先，您需要使用strtok分隔行。 在此處閱讀文檔。

獲得所需的所有字段后，使用snprintf它們輸出到一個字符串中

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

#define BUFFER_SIZE 1000

int main(){

    char tmp[BUFFER_SIZE];
    int count=0;
    char string[BUFFER_SIZE];
    char all_records[BUFFER_SIZE];
    char *name1, *name2, *name3, *type,*g1,*g2,*g3;

    FILE *fp=fopen("test.csv","r");
    while(fgets(tmp, BUFFER_SIZE,fp) != NULL){        
        name1 = strtok(tmp,",");
        name2 = strtok(NULL,",");
        name3 = strtok(NULL,",");
        type= strtok(NULL,",");
        g1= strtok(NULL,",");
        g2= strtok(NULL,",");
        g3= strtok(NULL,",");

        if (strstr(tmp, "name1")){
            count++;
    // snprintf is very similar to printf, see the reference [here][2]
            snprintf(string, BUFFER_SIZE,"\nName: %s, %s, %s \nType: %s\ng1 type: %s\ng2 type: %s\ng3 type: %s", name1, name2,name3,type,g1,g2,g3);
            strcat(all_records, string);              // combine new correct record
        }
    }
    snprintf(string, BUFFER_SIZE, "%d record(s) found.\n", count);
    strcat(string, all_records);   // add the number of records to the start
    // You can use the return value of snprintf to evaluate the size of all things you will print.
    printf("%s", string);
    return 0;
}