/* Copyright © 2025 TP-Link Systems Inc. * * file shell_main.c * brief * details * * author Zhu QingQing * version * date 06Aug25 * * history \arg */ /**************************************************************************************************/ /* DEFINES */ /**************************************************************************************************/ #include <stdio.h> #include <stdbool.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <signal.h> #include <sys/types.h> #include <sys/wait.h> #define SIZE_CMMD 1024 #define MAX_NUM_ARG 128 /**************************************************************************************************/ /* TYPES */ /**************************************************************************************************/ /**************************************************************************************************/ /* EXTERN_PROTOTYPES */ /**************************************************************************************************/ /**************************************************************************************************/ /* LOCAL_PROTOTYPES */ /**************************************************************************************************/ /**************************************************************************************************/ /* VARIABLES */ /**************************************************************************************************/ /**************************************************************************************************/ /* LOCAL_FUNCTIONS */ /**************************************************************************************************/ /* * fn static int exec_child(char *argv[]) * brief fork an child process to execute command * details * * param [in] argv - commands arr used for exec function * param [out] / * * return 0 - normal exit / -1 abnormal exit * retval * * note */ static int exec_child(char *argv[]) { /* fork child process to execute command */ int fds[2] = {-1 ,-1}; pid_t pid = -1; char dataPipe[SIZE_CMMD] = ""; int lenDataPipe = 0; if (pipe(fds) < 0) /* pipe: 0 - read data from pipe; 1 - write data to pipe */ { printf("pipe create faild.\n"); return -1; } pid = fork(); if (pid < 0) { printf("fork failed.\n"); return -1; } else if (0 == pid) { /* child proc */ /* write data from stdin to pipe */ close(fds[0]); if (dup2(fds[1], STDOUT_FILENO) < 0) { printf("child proc write data from stdin to pipe failed.\n"); return -1; } close(fds[1]); execvp(argv[0], argv); /* if execv successfully, child proc will be replaced */ printf("exec failed.\n"); /* else printf fail info */ return -1; } else { /* parent proc */ /* read port of pipe -> stdout */ close(fds[1]); lenDataPipe = read(fds[0], dataPipe, SIZE_CMMD); close(fds[0]); if (lenDataPipe < 0) { printf("pipe write failed.\n"); return -1; } /* the last char is '\n' */ dataPipe[lenDataPipe - 1] = '\0'; /* print data from child proc */ printf("%s\n", dataPipe); if (0 == strcmp(dataPipe, "stop")) { /* stop, then close child proc */ if (0 == kill(pid, SIGTERM)) { printf("close the child process successfully.\n"); return 0; } else { printf("close the child process failed.\n"); return -1; } } waitpid(pid, NULL, 0); } return 0; } /**************************************************************************************************/ /* PUBLIC_FUNCTIONS */ /**************************************************************************************************/ /**************************************************************************************************/ /* GLOBAL_FUNCTIONS */ /**************************************************************************************************/ /* * fn int main() * brief main function to achieve shell sample * details * * param [in] / * param [out] / * * return 0 * retval * * note */ int main() { printf("This is a shell sample ...\n"); printf("\n"); char cmmdShell[SIZE_CMMD] = ""; char *p_tmpArgs = NULL; char *p_saveArgs = NULL; char *p_endCharCmmd = NULL; char *argsCmmd[MAX_NUM_ARG] = {NULL}; /* save args that have been parsed */ int argsCnt = 0; /* number of args */ while (1) { /* obtain the standard input */ printf("root@shell: "); fflush(stdout); /*del \n in buffer*/ /* for scanf, '\n' will in stdin-buffer */ if (NULL == fgets(cmmdShell, SIZE_CMMD, stdin)) { printf("fgets error.\n"); break; } /* only \n, goto next loop */ if (0 == strcmp(cmmdShell, "\n")) { continue; } /* for fgets, 'cmmd\n' -> 'cmmd\n\0' */ p_endCharCmmd = strchr(cmmdShell, '\n'); if (NULL == p_endCharCmmd) { printf("fgets error.\n"); break; } else { *p_endCharCmmd = '\0'; /* not strlen -- end at \0 */ } /* exit */ if (0 == strcmp(cmmdShell, "exit")) { printf("Exit successfully.\n"); break; } /* parse command */ p_tmpArgs = strtok_r(cmmdShell, " ", &p_saveArgs); /* argsCnt < MAX_NUM_ARG - 1 -- last ele must be NULL */ while (p_tmpArgs != NULL && argsCnt < MAX_NUM_ARG - 1) { argsCmmd[argsCnt] = p_tmpArgs; argsCnt++; p_tmpArgs = strtok_r(NULL, " ", &p_saveArgs); /* only first use func strtok need pass para */ } argsCmmd[argsCnt] = NULL; /* end of argv[] in func exec must be NULL */ exec_child(argsCmmd); } return 0; } 哪里有问题