rendered paste body#include <stdio.h>#include <string.h>#include <math.h>#include <ctype.h>#include <stdlib.h>#include <errno.h>#include <sys/types.h>#include <dirent.h>#include <fcntl.h>#include <sys/stat.h>#define LINE_LENGTH 2048int grep_line(char[], char[], int, int);void write_line(char[], int);int fd = '\0';int rd = '\0';int wd = '\0';int filecount = 1;int matched_in_file = 0;DIR *dir;struct dirent *dirent;int main(int argc, char *argv[]){ char buffer[LINE_LENGTH*LINE_LENGTH]; char line[LINE_LENGTH]; { int temp = '\0'; temp = open("output.dat", O_WRONLY|O_TRUNC|0600); /*printf("%d", temp); perror("open"); char temp_buff[LINE_LENGTH]; memset(temp_buff, '\0', LINE_LENGTH); write(temp,temp_buff, strlen(temp_buff));*/ write(temp, "\0", 1); close(temp); } //printf("%d\n", argc); //printf("arg 0: %s, arg 1 %s, arg 2 %s\n", argv[0], argv[1], argv[2]); if(argc <= 2){ perror("Error: Insufficient arguments.\nUsage: mygrep PATTERN FILE\n"); return 1; } else if(argc > 3){ perror("Error: Too many arguments.\nUsage: mygrep PATTERN FILE\n"); return 1; } argv[1][strlen(argv[1])] = '\0'; argv[2][strlen(argv[2])] = '\0'; if(argc == 3){ int i = 0; while(i < strlen(argv[1])){ //printf("%c is alphanum? %d\n", argv[1][i], isalnum(argv[1][i])); if(!isalnum(argv[1][i])){ perror("Error: Argument 1 was not alphanumeric.\nUsage: mygrep PATTERN FILE\n"); return 1; } i++; } //printf("arg2 is %s\n", argv[2]); i = 0; while(i < strlen(argv[2])){ //printf("%c is alphanum? %d\n", argv[2][i], isalnum(argv[2][i])); if(!isalnum(argv[2][i])){ perror("Error: Argument 2 was not alphanumeric.\nUsage: mygrep PATTERN FILE\n"); return 1; } i++; } } if(argv[2]){ dir = opendir(argv[2]); } if(dir == '\0'){ perror("Error: Failed to open the directory.\nUsage: mygrep PATTERN FILE\n"); return 1; } dirent = readdir(dir); // here starts the magic int is_text_file = 0; while(dirent != '\0'){ is_text_file = 0; //printf("%s\n", dirent->d_name); chdir(argv[2]); if(dirent->d_type == 8){ //printf(" is regular.\n"); } else{ //printf("\n"); } { int i = 0; while(i < strlen(dirent->d_name)){ if(!strcmp(dirent->d_name + strlen(dirent->d_name) - 4, ".txt")){ //printf("%s is a .txt file.\n", dirent->d_name); is_text_file = 1; break; } else{ i++; } } } // read a file if(is_text_file){ memset(buffer, '\0', LINE_LENGTH*LINE_LENGTH); fd = open(dirent->d_name, O_RDONLY); if(fd == -1){ perror("Error: couldn't open file for reading."); return 1; } rd = read(fd, buffer, LINE_LENGTH*LINE_LENGTH*(sizeof(char))); //printf("File contents: %s\n", buffer); close(fd); } // split buffer into lines if(is_text_file){ { int i = 0; int j = 0; int linecount = 0; while(buffer[i] != '\0'){ if(buffer[i] == '\n'){ line[j] = '\0'; j = 0; i++; if(grep_line(line, argv[1], filecount, matched_in_file)){ if(matched_in_file == 0){ filecount++; } matched_in_file = 1; } linecount++; } else{ line[j] = buffer[i]; j++; i++; } } } } dirent = readdir(dir); matched_in_file = 0; } closedir(dir); return 0;}int grep_line(char line[], char pattern[], int n, int b){ int found = 0; //printf("considering line: %s\n", line); int i = 0; while(i < strlen(line) && i + strlen(pattern) < strlen(line)){ int match = 0; int z = 0; while(z < strlen(pattern)){ //printf("i + z is %d and strlen %d\n", i+z, strlen(line)); if(pattern[z] == line[i + z]){ match = 1; } else{ match = 0; break; } z++; } if(match == 1){ found = 1; } if(match && !b){ //printf("First match from %s\n", dirent->d_name); char temp_line[LINE_LENGTH]; char temp_int_str[17]; char temp_int_str2[17]; memset(temp_int_str, '\0', 17); memset(temp_int_str2, '\0', 17); memset(temp_line, '\0', LINE_LENGTH); int tmp; int tmp2; struct stat buf; if(stat(dirent->d_name, &buf) < 0){ perror("Error: Couldn't stat file"); return 0; } tmp = sprintf(temp_int_str, "%d", n); tmp2 = sprintf(temp_int_str2, "%d", buf.st_size); strcat(temp_line, "\n"); strcat(temp_line, temp_int_str); strcat(temp_line, "\t"); strcat(temp_line, dirent->d_name); strcat(temp_line, "\t"); strcat(temp_line, temp_int_str2); printf("%s\n", temp_line); write_line(temp_line, n); b = 1; } if(match){ printf("%s\n", line); write_line(line, n); break; } i++; } return found;}void write_line(char line[], int n){ char buffer[LINE_LENGTH]; int wd; wd = open("output.dat", O_WRONLY|O_CREAT|O_APPEND,0700); strcpy(buffer, line); write(wd, buffer, strlen(buffer)); write(wd, "\n", 1); close(wd);}