更改数组的值，但最终导致最后两个值重复

问：

我正在编写的程序的一部分将数组中的某个值替换为数组中的下一个值。但是，它最终导致数组中的最后两个值相同。有没有办法将最后一个值替换为 NULL？

这是当前输出

found it again
Array value 0: cat:
Array value 1: file1.txt:
Array value 2: output.txt:
Array value 3: output.txt:
Array value 4: (null):
Array value 5: (null):
This is the first line in file1.txt
This is the last line

这是我尝试替换最后一个值时的输出将 null，但它返回分段错误

found it again
Array value 0: cat:
Array value 1: file1.txt:
Array value 2: output.txt:
Array value 3: (null):
Array value 4: (null):
Array value 5: (null):

这是完整的代码

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <string.h>

#define BUFFERSIZE 1024

int main(int argc, char* argv[])
{
    int fd_out = dup(STDOUT_FILENO);
    int fd_in = dup(STDIN_FILENO);
    
    argc++;

    char buf[BUFFERSIZE];
    int n;
        printf("Please enter commands: \n");

    while ((n = read(STDIN_FILENO, buf, BUFFERSIZE)) > 0)
        {
        buf[n] = 0;
        buf[strlen(buf)-1] = '\0';
        int i = 0;
        char* array[10];
        char* token1 = strtok(buf, " ");

        while ((token1 != NULL))
        {
            array[i++] = token1;
            token1 = strtok(NULL, " ");
            
        }//while

        array[i] = NULL;

        if (strcmp(buf, "exit") == 0)
        {
            break;
        }//if
        
        for (int j = 0; j < i; j++) 
        {
            if (!strcmp(array[j], ">"))
            {
                char* filename_out = array[j+1];
                printf("STDOUT redirected\n");
                printf("found it\n");
                int file_out = open(filename_out, O_WRONLY | O_CREAT, 0777);
                int file2_out = dup2(file_out, 1);
                
                for(int k = j; k < i-1; k++)
                {
                    array[k] = array[k + 1];
                }//if
                
                array[i] = NULL;
                printf("found it again\n");

                if ((file_out | file2_out) == -1)
                {
                    return 1;
                }//if

                //array[i-1] = NULL;

                            for (int j = 0; j < i+2; j++)
                            {
                                    printf("Array value %d: %s:\n", j, array[j]);
                            }//for*/
            }//if
            if (!strcmp(array[j], "<"))
            {
                char* filename_in = array[j+1];
                printf("STDIN_FILENO redirected\n");
                int file_in = open(filename_in, O_WRONLY | O_CREAT, 0777);
                int file2_in = dup2(file_in, 0);

                                for(int l = j; l < i - 1; l++)
                                {
                                        array[l] = array[l + 1];
                                }//for
                
                if ((file_in | file2_in) == -1)
                {
                    return 1;
                }//if
            }
        }//for

            for (int i = 1; i < argc; i++)
            {
            pid_t pid;
            
            if (argc >= 1) 
            {
                if ((pid = fork()) < 0) 
                {
                    perror("fork");
                }//if
                else if (pid == 0) 
                { // child process
                    if (execvp(array[0], array) == -1) 
                    {
                        perror("execvp");
                        return EXIT_FAILURE;
                    } // if
                }//else if
                else 
                {   // parent process
                    int status;
                    wait(&status);
                    //int again_out = dup2(fd_out, 1);
                    //int again_in = dup2(fd_in, 0);
                    if ((again_out | again_in) == -1)
                    {
                        return 1;
                    }
                    printf("Please enter commands again: \n");
                    
                }//else     
            }//if
            else 
            {
                fprintf(stderr, "Please specify the name of the program to exec as a command line argument\n");
                return EXIT_FAILURE;
            }//if
        }//for
    }//while
    if (n == -1) perror("read");
}//main

我尝试使用（其中是数组的大小），但它返回分段错误array[i-1] = NULL;i