简单的shell C程序 源码 可执行文件

#define _GNU_SOURCE #include <stdio.h> #include <ctype.h> #include <unistd.h>//include the function"get_current_dir_name""fork""execv""getpid""wait""sleep""access""chdir" #include <string.h> #include <stdlib.h>//include the function"free""atoi" #include <sys/types.h>//include the type"pid_t""open" #include <sys/stat.h>//include the function"open" #include <sys/wait.h>//define the function"wait" #include <signal.h>//include the function"kill" #include <fcntl.h>//include the function"open" #include <stdlib.h> #include "ysh.h" #define TRUE 1 #define FALSE 0 #define MaxLen 40 #define NO_PIPE -1 #define FD_READ 0 #define FD_WRITE 1 char tokenString[MaxLen+1]; int new_flag;//to show that a new command begin; int end_flag;//to show if exit is performed typedef enum{ END,INPUT,OUTPUT,PIPE,BACK,STRING,ERROR }TokenType; typedef enum{ START,INSTRING,DONE }StateType; typedef enum{ BEGIN,PROGA,PROGB,INR,OUTR,FINISH }StepMark; struct result{ int kind;//represent different struct char *filein; char *fileout; int n;//used for pipe }; int getaline(int fd,char *buf); void getenviron(int n,char *s); void init_environ(); TokenType getToken(); void analyze(); int is_founded(char *cmd); void cd_cmd(char *cmd); void add_node(char *input_cmd,int node_pid); void bg_cmd(int job_num); void fg_cmd(int job_num); void jobs_cmd(); void ctrl_z(); void del_node(int sig,siginfo_t *sip,void *notused); void setflag(); void clean(); int perform_normal(); int perform_special(); struct result *direction; char *argv[10][10];//store the parameters int is_bg; int echo_status=0; int curpath;//store the current path number int main() { char c,*path; int input_len,is_pr,pid; int i; init_environ(); curpath=0; while(1){ input_len=0; is_bg=0; new_flag=1; struct sigaction action; action.sa_sigaction=del_node; sigfillset(&action.sa_mask); action.sa_flags=SA_SIGINFO; sigaction(SIGCHLD,&action,NULL); signal(SIGTSTP,ctrl_z); /*****Print the Prompt*****/ path=get_current_dir_name(); envpath[curpath]=(char *)malloc(strlen(path)+2);//? strcpy(envpath[curpath],path); strcat(envpath[curpath],"/"); envpath[curpath+1]=NULL; printf("ysh@%s>",path); /*****Get the user's input*****/ while((c=getchar()) == ' ' || c == '\t' || c == EOF)//EOF??? ; if(c == '\n') continue; while(c != '\n'){ buf[input_len++] = c; c=getchar(); } buf[input_len]='\0'; input = (char *)malloc(input_len+1); strcpy(input,buf); /*****Parse the Command*****/ analyze(); /*****Perform the command*****/ if(direction == NULL) continue; else{ /*Command:exit*/ if(strcmp(argv[0][0],"exit") == 0){ //while(head != NULL){ // kill(head->pid,SIGKILL); // head=head->link; //} printf("GoodBye!\n"); clean(); break; } /*Command:jobs*/ if(strcmp(argv[0][0],"jobs") == 0){ jobs_cmd(); clean(); continue; } /*Command:fg*/ if(strcmp(argv[0][0],"fg") == 0){ if(argv[0][1][0] != '%'){ printf("error:the command 'fg' doesn't have the symbol '%'!\n"); clean(); continue; } for(i=0; argv[0][1][i] != '\0'; i++) argv[0][1][i]=argv[0][1][i+1]; fg_cmd(atoi(argv[0][1])); clean(); continue; } /*Command:bg*/ if(strcmp(argv[0][0],"bg") == 0){ if(argv[0][1][0] != '%'){ printf("error:the command 'bg' doesn't have the symbol '%'!\n"); clean(); continue; } for(i=0; argv[0][1][i] != '\0'; i++) argv[0][1][i]=argv[0][1][i+1]; bg_cmd(atoi(argv[0][1])); clean(); continue; } /*Command:echo*/ if(strcmp(argv[0][0],"echo") == 0){ if(strcmp(argv[0][1],"$status") == 0) printf("%d\n",echo_status); else printf("error:the command 'echo' isn't written rightly!\n"); clean(); continue; } /*Command:cd*/ if(strcmp(argv[0][0],"cd") == 0){ cd_cmd(argv[0][1]); clean(); continue; } if(direction->kind == 1){ if(is_founded(argv[0][0]) == 0){ printf("error:this command is not found!\n"); clean(); continue; } perform_normal();//no pipe }else perform_special();//with pipe } } return 0; } /*****Initialize the program*****/ int getaline(int fd, char *buf) { int i=0; char c; while(read(fd,&c,1)){ buf[i++]=c; if(c == '\n'){ buf[i-1]='\0'; return i; } } return i; } void getenviron(int n,char *s) { int i,j,k; char c,buff[80],*p; i=k=j=0; while((c=s[i]) != '=') buff[i++]=c; buff[i++]='\0'; if(strcmp(buff,"PATH") == 0){ while(s[i] != '\0'){ if(s[i] == ':'){ buff[j++]='/'; buff[j]='\0'; p=(char *)malloc(strlen(buff)+1); strcpy(p,buff); envpath[k++]=p; envpath[k]=NULL; curpath=k; j=0; i++; }else{ buff[j]=s[i]; j++; i++; } } }else printf("error:no match\n"); } void init_environ() { int fd,n,i; char buf[80]; if((fd=open("ysh_profile",O_RDONLY,660)) == -1){ printf("init environ variable error!\n"); exit(1); } envpath[0]=NULL; curpath=0; while(n=getaline(fd,buf)) getenviron(n,buf); head=end=NULL; } /*****Implement Function:scan*****/ TokenType getToken() { int tokenStringIndex; TokenType currentToken; StateType state=START; int save; static int i; char c; tokenStringIndex=0; if(new_flag == 1) i=0; while(state != DONE){ new_flag=0; c=input[i++]; save=TRUE; switch(state){ case START: if( c == ' ' || c == '\t') save = FALSE; else if(isdigit(c) || isalpha(c) || c == '_' || c == '.' || c == '%' || c == '$') state=INSTRING; else{ save=FALSE; state=DONE; switch(c){ case '<': currentToken=INPUT; break; case '>': currentToken=OUTPUT; break; case '|': currentToken=PIPE; break; case '&': currentToken=BACK; break; case '\0': currentToken=END; break; default: currentToken=ERROR; printf("symbol %c can't be discerned!\n",c); break; } } break; case INSTRING: if(!isdigit(c) && !isalpha(c) && c != '_' && c != '.' && c != '%'){ state=DONE; i--; save=FALSE; currentToken=STRING; } break; default: printf("Scanner Bug: state=%d\n",state); state=DONE; currentToken=ERROR; break; } if(save && tokenStringIndex <= MaxLen) tokenString[tokenStringIndex++]=c; if(state == DONE) tokenString[tokenStringIndex]='\0'; } return currentToken; } void analyze() { StepMark step; TokenType token; int i,j; step=BEGIN; i=j=0; direction=(struct result *)malloc(sizeof(struct result)); direction->filein=NULL; direction->fileout=NULL; argv[i][j]=NULL; while(step != FINISH){ token=getToken(); switch(step){ case BEGIN: if(token == STRING){ direction->kind=1; step=PROGA; direction->n=1; argv[i][j]=(char *)malloc(strlen(tokenString)+1); strcpy(argv[i][j++],tokenString); argv[i][j]=NULL; }else if(token == END){ step=FINISH; clean(); }else{ step=FINISH; clean(); printf("error: the command can't be analyzed!\n"); } break; case PROGA: switch(token){ case STRING: argv[i][j]=(char *)malloc(strlen(tokenString)+1); strcpy(argv[i][j++],tokenString); argv[i][j]=NULL; break; case INPUT: step=INR; break; case OUTPUT: step=OUTR; break; case PIPE: direction->kind=2; step=PROGB; argv[i][j]=(char *)malloc(1);//????? argv[i][j++]=(char *)0; argv[i][j]=NULL; i++; j=0