C: как получить пользовательский ввод без ввода ENTER (\ n)?

Question

Я пытаюсь прочитать строку ввода пользователя, которая будет записывать ключи ввода пользователя только без '\ n'.

Итак, разделив команду и аргумент, который вводит пользователь, например. «mkdir hello» («mkdir» = command, «hello» = argument) возвращает аргумент («hello \ n»).

Есть ли способ эффективно удалить '\ n'?

Кроме того, как вы обнуляете строки?

int main(void) { 

    char directoryName[129] = ""; 

    printf("\nProgram Start... \n\n"); 

    // getting user input string 
    // and splitting command and argument 
    char inputString[129]; 
    char delimiter[] = " "; 
    char *line; 
    char *arg; 
    struct tree_node *root = make_tree_node("root\0"); 
    //struct tree_node *cwd = make_tree_node("root\0"); 
    struct tree_node *cwd = root; 

    printf("/%s >", directoryName); 

    while (fgets(inputString, 128, stdin)) { 

     // char * before strsep, set pointer to be original checkString 
     // original checkString 
     // then free memory 

     // gets argument and stores as arg 
     line = malloc(sizeof(char) * strlen(inputString)); 
     strcpy(line, inputString); 
     arg = strsep(&line, delimiter); 
     arg = strsep(&line, delimiter); 
     printf("your argument: %s\n", arg); 

     printf("/%s >", directoryName); 
} 

Весь код:

#include <stdio.h> /* For fgets(), fprintf() and printf() */ 
#include <stdlib.h> /* For EXIT_FAILURE */ 
#include <ctype.h> /* For isspace() */ 
#include <string.h> 
#include <stddef.h> 

// COMMANDS 
char exitProgram[] = "exit"; 
char listDirectory[] = "ls"; 
char commandDirectory[] = "cd"; 
char makeDirectory[] = "mkdir"; 
char removeDirectory[] = "rmdir"; 

// holds a string buffer of length 128 
// a pointer to its parent 
// a pointer to the first node of the list of children 
typedef struct tree_node { 
    char string_buffer[128]; 
    struct tree_node *parent; 
    struct list_node *first_child; // first node of list of children? 
} tree_node; 

// pointer to tree node 
// pointer to next item in the list 
typedef struct list_node { 
    struct tree_node *tree; 
    struct list_node *next; 
} list_node; 

// allocates the right amount of space for a tree node 
// sets the pointers to NULL 
// initialises the string buffer with the given name 
// returns a pointer to the tree node 
struct tree_node *make_tree_node(char *name) { 
    tree_node *tree = malloc(sizeof(*tree)); 
    tree -> parent = NULL; 
    tree -> first_child = NULL; 
    strcpy(tree -> string_buffer, name); 
    return tree; 
} 

// allocates a new list node 
// assigns the fields for the tree node it references and the next list node 
// returns a pointer to the new list node 
struct list_node *make_list_node(struct tree_node *v, struct list_node *next) { 
    list_node *instance = malloc(sizeof(*instance)); 
    instance -> tree = v; 
    instance -> next = next; 
    return instance; 
} 

// checks whether directory named arg already exists in current working directory 
// creates the directory if it does not exist 
// if arg is NULL, the function should print an error message 
void do_mkdir(struct tree_node *cwd, char *arg) { 

    printf("Making Directory with name %s \n", arg); 

    // check if directory exists 
    struct list_node *subDir = cwd->first_child; 

    while (subDir != NULL) { 
     if (strcmp(subDir->tree->string_buffer, arg) == 0) { 
      printf("Directory with that name exists. Please provide another name.\n"); 
      return; 
     } 
     subDir = subDir->next; 
    } 

    // adding new directory 
    struct tree_node *newSubDir = make_tree_node(arg); 
    newSubDir->parent = cwd; 
    struct list_node *newListNode = make_list_node(newSubDir, NULL); 

    // putting new node in alphabetical order 
    struct list_node *prev = NULL; 
    if (subDir == NULL) { 
     newListNode->next = cwd->first_child; 
     cwd->first_child = newListNode; 
    } else { 
     while (subDir != NULL) { 
      // TODO: use case insensitive compare 
      if (strcmp(arg, subDir->tree->string_buffer) > 0) { 
       // inserting in front 
       newListNode->next = subDir->next; 
       prev->next = newListNode; 
       break; 
      } 
      prev = subDir; 
      subDir = subDir->next; 
     } 
     if (subDir == NULL) { 
      subDir->next = newListNode; 
     } 
    } 
    printf("Directory added: %s", arg); 
} 

// prints all children of the directory cwd (not recursively) 
void do_ls(struct tree_node *cwd) { 
    printf("Listing Directories...\n"); 
    struct list_node *subDir = cwd -> first_child; 
    while (subDir != NULL) { 
     printf("%s", subDir ->tree -> string_buffer); 
     subDir = subDir->next; 
    } 
} 

// *checks whether cwd has a subdirectory named arg 
// *if yes, the function returns the corresponding tree node (and become new working directory) 
// *if no, prints an error message 
// *handle cd and cd .. 
struct tree_node *do_cd(struct tree_node *cwd, struct tree_node *root, char *arg) { 

    // checks if cwd has a subdirectory named arg 
    struct list_node *subDir = cwd -> first_child; 

    while (subDir != NULL) { 
     if (strcmp(subDir->tree->string_buffer, arg) == 0) { 
      printf("Subdirectory exists: Entering!\n"); 
      subDir->tree = cwd; 
      printf("Making subdirectory current working directory: name = %s\n", arg); 
      printf("Returning current working directory: %s.\n", arg); 
      return cwd; 
     } 
     subDir = subDir->next; 
    } 
    printf("Directory does not exist!\n"); 
    return NULL; 
} 

// *prints the prompt (e.g. /bar/baz/ >) in every iteration of the main loop 
// *show all directories on the path in correct order 
//void show_prompt(struct tree_node *cwd) { 

// while(cwd != NULL) { 
//  printf(cwd->string_buffer); 
     //show all directories on the path in correct order. 
// } 
// printf("/"); 
//} 

// *removes a node child from its parent node dir 
// *take care to correctly support corner cases like the child being the only one 
// *all memory occupied by the child should be freed 
//void remove_child(struct tree_node *dir, struct tree_node *child) { 
// if (dir == NULL) { 
//  printf("Current directory is empty!"); 
// } 
// else if (dir -> child != NULL) { 
//  free(child); 
// } 
//} 

// implement rmdir (follow same pattern as previous exercise) 
// *if the specified directory is not empty, rmdir should fail with an error message 
//void do_rmdir(struct tree_node *cwd, char *arg) { 
// if(cwd != NULL) { 
//  printf("Specified directory is not empty!"); 
// } else { 
//  free(cwd); 
// } 
//} 

int main(void) { 

    char directoryName[129] = ""; 

    printf("\nProgram Start... \n\n"); 

    // getting user input string 
    // and splitting command and argument 
    char inputString[129]; 
    char delimiter[] = " "; 
    char *line; 
    char *arg; 
    struct tree_node *root = make_tree_node("root\0"); 
    //struct tree_node *cwd = make_tree_node("root\0"); 
    struct tree_node *cwd = root; 

    printf("/%s >", directoryName); 

    while (fgets(inputString, 128, stdin)) { 

     // char * before strsep, set pointer to be original checkString 
     // original checkString 
     // then free memory 

     // gets argument and stores as arg 
     line = malloc(strlen(inputString) + 1); 
     strcpy(line, inputString); 
     arg = strsep(&line, delimiter); 
     arg = strsep(&line, delimiter); 
     printf("your argument: %s\n", arg); 

     printf("/%s >", directoryName); 

     //printf("userInput:%s", inputString); 

     if(strncmp(inputString, "exit", 4) == 0) { 
      printf("Breaking...\n"); 
      break; 
     } 

     ////////////////////////////// HANDLING LS //////////////////////////// 

     else if(strncmp(inputString, "ls ", 3) == 0) { 
      printf("The ls command should be used without arguments.\n"); 
     } 

     else if(strncmp(inputString, "ls", 2) == 0) { 
      do_ls(cwd); 
      printf("/%s >", directoryName); 
     } 

     ////////////////////////////// HANDING CD ///////////////////////////// 
     else if(strncmp(inputString, "cd ..", 5) == 0) { 
      printf("Returning to previous directory.\n"); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "cd .", 4) == 0) { 
      printf("Returning to current directory.\n"); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "cd ", 3) == 0) { 
      do_cd(cwd, root, arg); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "cd", 2) == 0) { 
      printf("Returning to root directory.\n"); 
      printf("/%s >", directoryName); 
     } 

     /////////////////////////// HANDLING MKDIR ///////////////////////////// 
     else if(strncmp(inputString, "mkdir ", 7) == 0) { 
      printf("Please specify directory name that is not NULL: mkdir directoryName\n"); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "mkdir ", 6) == 0) { 
      do_mkdir(cwd, arg); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "mkdir", 5) == 0) { 
      printf("Please specify directory name: mkdir directoryName\n"); 
      printf("/%s >", directoryName); 
     } 

     //////////////////////// HANDLING RMDIR ///////////////////////////////// 
     else if(strncmp(inputString, "rmdir ", 7) == 0) { 
      printf("Please specify directory name that is not NULL: rmdir directoryName\n"); 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "rmdir ", 6) == 0) { 
      printf("Removing Directory with name...\n"); 
      // 
      printf("/%s >", directoryName); 
     } 
     else if(strncmp(inputString, "rmdir", 5) == 0) { 
      printf("Please specify directory name: rmdir directoryName\n"); 
      printf("/%s >", directoryName); 
     } 
     else { 
      printf("Unrecognised input: Please try again.\n"); 
      printf("/%s >", directoryName); 
     } 
    } 

    printf("\nProgram Quit... \n\n"); 


    return 0; 
} 

Answer 1

Вы можете использовать:

while (fgets(inputString, 128, stdin)) { 
    inputString[strlen(inputString)-1] = '\0'; 
    ... 

Старается своей программой с моими изменениями, выход Пример:

Program Start... 

/>mkdir hello 
your argument: hello 
/>Making Directory with name hello 
Directory added: hello/ >