读取文件并提取C中两行特定文本之间的行

Question

I am trying to extract text that is in between [HOCKEY] and [done with HOCKEY] from the following file:

sport.txt :

[HOCKEY]
a=10
b=20
c=30
d=45
[done with HOCKEY]
[SOCCER]
a=35
b=99
c=123
d=145
[done with SOCCER]

With the following code I will be able to check if the line is [HOCKEY] but I am unable to record the location of 1st line and last line between [HOCKEY] and [done with HOCKEY]

#include<stdio.h>
int main()
{
FILE *infile;
char start, end;
char *sport="[]";
char line_buffer[BUFSIZ]; /* BUFSIZ is defined if you include stdio.h */
int line_number,i;
infile = fopen("sport.txt", "r");
printf("Opened file  for reading\n");
line_number = 0;
while (fgets(line_buffer, sizeof(line_buffer), infile)) {
    ++line_number;
    /* note that the newline is in the buffer */
    if (line_buffer=="[HOCKEY]")
    {
    start=line_buffer;
    printf("Found start %s",start);
  }
      if (line_buffer=="[done with HOCKEY]")
    end=line_buffer;

    while(start<end){
    printf("%c",start);
    start++;
    system("PAUSE");
    }
}
return 0;
}

Answer 1

1. First line is the first line after [HOCKEY] . And

2. Last line is the last line before [done with HOCKEY] .

So what you need is to read the file one line by one line. When you read [HOCKEY] , you are approaching the real data you need and start to read and store the data from next line. Continue this step until you read [done with HOCKEY] and stop.

Answer 2

int count = 0;
char found_it = 0;
char *wordStart = "[HOCKEY]";
char *wordStop = "[done with HOCKEY]";
int charCount = strlen(wordStart);
while((c = getc(fptr)) != EOF){
    if( c == wordStart[count] ){
        count++;

        if(count == charCount){printf("Found [HOCKEY] \n"); found_it = 1; break;}
    }
    else{
        count = 0;
    }
}

if(!found_it){printf("Did not find [HOCKEY] \n"); return 0;}

count = 0; found_it = 0;
charCount = strlen(wordStop);
while((c = getc(fptr)) != EOF){
    printf("%c", c);
    if( c == wordStop[count] ){
        count++;

        if(count == charCount){found_it = 1; break;}
    }
    else{
        count = 0;
    }
}

if(!found_it){printf("Did not find [done with HOCKEY] \n");}
return 0;

Answer 3

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

int main(){
    FILE *infile;
    fpos_t start, end, pre_pos;
    char line_buffer[BUFSIZ]; /* BUFSIZ is defined if you include stdio.h */
    //char line_buffer[128]; // BUFSIZ : I do not know if there is a large enough

    infile = fopen("sport.txt", "r");
    if(infile)
        printf("Opened file  for reading\n");
    else {
        perror("file open");
        return -1;
    }
    fgetpos(infile, &pre_pos);
    end = start = pre_pos;
    while (fgets(line_buffer, sizeof(line_buffer), infile)) {
        if (strcmp(line_buffer, "[HOCKEY]\n")==0){
            fgetpos(infile, &start);
        } else if (strncmp(line_buffer, "[done with HOCKEY]", 18)==0){//18 == strlen("[done with HOCKEY]");
            end=pre_pos;
            break;
        }
        fgetpos(infile, &pre_pos);
    }
    fsetpos(infile, &start);
    while(start<end){
        printf("%c", fgetc(infile));
        fgetpos(infile, &start);
    }
    fclose(infile);
    system("PAUSE");
    return 0;
}