C/Linux - 扫描文本文件中的行以查找特定单词

Question

所以我试图弄清楚如何扫描文本文档中的行以查找单个单词。关键字来自文本文件并存储在结构中。同一文件还包含一个目录，用于扫描要在其中扫描该关键字的文件。我的程序可以从请求文件中读取并打开指定的目录。它还可以查看其中有哪些文件。此时，它在尝试扫描文件并将其打印回给用户的过程中出现 SegFault 错误。任何帮助将非常感激。

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <dirent.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>

/* Structs */
struct input
{
    char match[6];
    char path[100];
    char key[20];
};

/* Variables */
//char match[6];
//char path[100];
//char key[20];
int last = 0;
int linen = 1;
char filename[100];
char top[256];
int x = 0;
static int MAXLINESIZE = 1000;
static int MAXDIRNAME = 200;
static int MAXKEYWORD = 1000;

struct input insave[50];

/* Prototypes */
void readfile();
void readtdir();
void scanfile();

/* Methods */
//Scan directory in in.txt file for text files to scan
void readtdir()
{
    DIR *dir;
    struct dirent *dirr;
    char temp[256];


    for(x = 0; x < last; x++)
    {
        dir = opendir(insave[x].path);
        strcpy(top, insave[x].path);
        printf("\nOpened: %s\n", insave[x].path);
        //printf("dir: %s\n", top);
        if(dir != NULL)
        {
            while((dirr = readdir(dir)) != NULL)
            {
                if(!(strcmp(dirr->d_name,"..")))
                {
                    continue;
                }
                else
                {
                    if(!(strcmp(dirr->d_name,".")))
                    {
                        continue;
                    }
                    else
                    {
                        printf("%s\n",dirr->d_name);

                        if(dirr->d_type == 8)
                        {
                            sprintf(temp, "%s", dirr->d_name);
                            printf("%s\n", temp);
                            strcpy(filename, temp);
                            scanfile(filename);
                        }
                    }
                }
            }
        }
        closedir(dir);
    }
    return;
}

//Scan lines of individual file for keyword
void scanfile(char *argv)
{
    FILE *fRead;
    char line[MAXLINESIZE];
    char templine[MAXLINESIZE];
    int y = x;

    fRead = fopen(argv, "r+");

    if(fRead == NULL)
    {
        printf("File cannot be opened");
    }
    else
    {
        while(fgets(line,MAXLINESIZE,fRead) != NULL)
        {
            strcpy(templine, line);
            if(strstr(templine,insave[y].key) != NULL)
            {
                printf("%s:%d:%s", filename, linen, line);
            }
            linen++;
        }
    }
    fclose(fRead);
}

//Read in.txt file for commands
void readfile(char *argv)
{
    FILE *pRead;
    int x = 0;
    char match[6];
    char path[100];
    char key[20];

    pRead = fopen(argv, "r+");

    if(pRead == NULL)
    {
        printf("File cannot be opened");
    }
    else
    {
        while(!feof(pRead))
        {
            if(fscanf(pRead, "%5s%99s%19s", match, path, key) != 3)
            {
                break;
            }
            else
            {
                strcpy(insave[x].match, match);
                strcpy(insave[x].path, path);
                strcpy(insave[x].key, key);
                x++;
                last = x;
            }
        }
    }
    fclose(pRead);
}

int main(int argc, char *argv[])
{
    int x = 0;
    argv[1] = "5";   //only used for testing purposes
    argv[2] = "in.txt";   //only used for testing purposes

    readfile(argv[2]);
    readtdir();

    printf("\n\n");
    for(x = 0; x < last; x++)
    {
        printf("This is: %s\n",insave[x].match);
        printf("This is: %s\n",insave[x].path);
        printf("This is: %s\n\n",insave[x].key);
    }
    return 0;
}

Answer 1

一些想法:

而不是神奇的数字 100

#include <limits.h>
// If NAME_MAX does not exist, try something like 1024 – 100 is small.
// At least during debug
char filename[NAME_MAX + 1];

而不是神奇的数字 256

// char temp[256];
struct dirent temp;
…
sprintf(temp.d_name, "%s", dirr->d_name);
printf("%s\n", temp.d_name);
strcpy(filename, temp.d_name);

不需要char templine[MAXLINESIZE]; ，只需使用 strstr(line,insave[y].key) .

在 main() ，删除while(!feof(pRead)) 。它没有任何作用。直到您尝试读取但什么也没得到之后，才会检测到 EOF，在这种情况下，您的 fscanf() 会被检测到。已经返回 EOF 并且您将 break .

保险0 <= x < 50对于 insave[x] .

而不是 if(dirr->d_type == 8) ，使用DT_REG .

不要做

argv[1] = "5";   //only used for testing purposes
argv[2] = "in.txt";

你不知道有多大argv是。相反:

char *my_argv[4];
my_argv[0] = argv[0];
my_argv[1] = "5";   //only used for testing purposes
my_argv[2] = "in.txt";
my_argv[3] = NULL;
readfile(my_argv[2]);