Dec 16
公布期末设计Smallshell的完整源代码：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 | /* ************************************************* * * Small shell on Unix/Linux * * This shell finished all the functions which * are required. And I added new inner functions * "help" and "exit" by myself. * * Enjoy it! * * author: Longqianzhi 용성지 * Stu_ID: 12094817 * data: Dec/27/2010 * * *************************************************/#include <errno.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/wait.h>#include <fcntl.h>#include <signal.h>#define MAX_CMD_ARG 10#define MAX_CMD_LIST 10const char *prompt = "# ";char* cmdlist[MAX_CMD_LIST];char* cmdargs[MAX_CMD_ARG];char cmdline[BUFSIZ];void fatal(char *str);void execute_cmd(char *cmd);void execute_cmdline(char* cmdline);int makeargv(char *s, const char *delimiters, char** argvp, int MAX_LIST);void help();void cd(char *path);void catchint(int);void join(); /* Use one pipe to communication.*/int join2(); /* Use two pipe to communication.*/int dpipe_test(); /* It's useless.Just for test.*/void parse_filter(char *cmd); /* A filter for argument*/int main(int argc, char**argv){ int i=0; static struct sigaction act; /*Cope with the signal*/ act.sa_handler=catchint; sigfillset(&(act.sa_mask)); sigaction(SIGINT,&act,NULL); sigaction(SIGQUIT,&act,NULL); while (1) { fputs(prompt, stdout); fgets(cmdline, BUFSIZ, stdin); cmdline[ strlen(cmdline) -1] ='\0'; execute_cmdline(cmdline); printf("\n"); } return 0;}void fatal(char *str){ perror(str); exit(1);}void execute_cmdline(char* cmdline){ int count = 0; int i=0; count = makeargv(cmdline, "!", cmdlist, MAX_CMD_LIST); /* Execute the commands with different way.*/ /*Just a single command.*/ if(count==1){ /* First of all,try to make sure whether * the command is "cd". */ if(cmdlist[0][0]=='c'&&cmdlist[0][1]=='d'){ parse_filter(cmdlist[0]); count = makeargv(cmdlist[0], " \t", cmdargs, MAX_CMD_ARG); if(!strcmp("cd",cmdargs[0])){ if(chdir(cmdargs[1])) fatal("cd"); return; } } /* Fork a child process to run every * commands except "cd" */ switch(fork()) { case -1: fatal("fork error"); case 0: execute_cmd(cmdlist[0]); default: wait(NULL); fflush(stdout); } } /*Execute two programs with a pipe.*/ if(count==2){ join(); } /*Execute three programs with two pipes.*/ if(count==3){ join2(); } /*There are too many commands*/ if(count>=4){ printf("Too many pipes!\n"); return; }}/* ***************************************** * Execute a single commands with arguments. * * *****************************************/void execute_cmd(char *cmd){ int i=0; int count = 0; parse_filter(cmd); count = makeargv(cmd, " \t", cmdargs, MAX_CMD_ARG); /* * Recognize some inner functions * like cd,help,exit and so on. * Also you can add some new inner * functions by yourself here. * */ if(!strcmp("help",cmdargs[0])){ help(); return ; } if(!strcmp("exit",cmdargs[0])){ kill(getppid(),SIGKILL); /*kill parent process*/ raise(SIGKILL); /*kill myself*/ exit(0); } execvp(cmdargs[0], cmdargs); fatal("exec error");}/* ***************************************** * Count the arguments'number in a command. * * ***************************************/int makeargv(char *s, const char *delimiters, char** argvp, int MAX_LIST) { int i = 0; int numtokens = 0; char *snew = NULL; if( (s==NULL) || (delimiters==NULL) ) return -1; snew = s + strspn(s, delimiters); if( (argvp[numtokens]=strtok(snew, delimiters)) == NULL ) return numtokens; numtokens = 1; while(1){ if( (argvp[numtokens]=strtok(NULL, delimiters)) == NULL) break; if(numtokens == (MAX_LIST-1)) return -1; numtokens++; } return numtokens;}/* ********************************* * Inner fnuction: help(). * Show some infomations to the stdin * ***********************************/void help(){ printf("\n * *************************************** *"); printf("\n * *"); printf("\n * WELCOME TO SMALL SHELL ! *"); printf("\n * *"); printf("\n * *************************************** *"); printf("\n * *"); printf("\n * There are 3 inner functions in shell. *"); printf("\n * *"); printf("\n * 1) cd :Change the current directory. *"); printf("\n * 2) exit :Quit from the small shell. *"); printf("\n * 3) help :Show this message for help. *"); printf("\n * *"); printf("\n * IF YOU FIND ANY BUGS OR *"); printf("\n * HAVE ANY QUESTIONS *"); printf("\n * *"); printf("\n * mail to me:longqianzhi@gmail.com *"); printf("\n * *"); printf("\n * *************************************** *\n"); exit(0);}/* *************************** * Inner function:cd(). * Change the current directory. * * ***************************/ void cd(char *path){ if(chdir(path)) fatal("cd");}/* ************************************ * The function about act.sa_handler * If press the Ctrl+c, resume the shell. * * ************************************/ void catchint(int signo){ printf("\nReceive a signo=%d\n",signo); printf("Returning to the shell\n"); /* Init the cmdline Array. * If not,the shell will try to run * commands in the memory. */ cmdline[0]='\0';}/* ************************************ * An easy way to use double pipe. * * But this function is just for test and * debug in the project,because I wrote * a new one by myself. The new one is * called "join2". * * ***********************************/int dpipe_test(){ /*build command string with normal format.*/ char newstr[128]; strcpy(newstr,cmdlist[0]); strcat(newstr,"|"); strcat(newstr,cmdlist[1]); strcat(newstr,"|"); strcat(newstr,cmdlist[2]); /*call system shell to run the commmands*/ system(newstr); return 0;}/* ************************************** * Delete special character from argument. * If there is any special charater, * this function will change them to '\32' * * ***************************************/ void parse_filter(char *cmd){ int i=0; int CMAX=strlen(cmd); while(cmd[i]!=' '&&i<CMAX) i++; if((++i)<CMAX){ if (cmd[i++]=='-') { while(cmd[i]!=' '&&i<CMAX){ if(cmd[i]<'0'||(cmd[i]>'9'&&cmd[i]<'A')|| (cmd[i]>'Z'&&cmd[i]<'a')||cmd[i]>'z'){ char tmp=cmd[i-1]; cmd[i]=tmp; } i++; } } } }/* *********************************** * Link the child process's stdout to * grandchild process's stdin with pipe. * * ***********************************/ void join(){ int p[2],status; switch (fork()){ case -1:fatal("1st fork call in join()"); case 0:break; default:wait(&status); return; } /* Try to make a new pipe.*/ if(pipe(p)==-1) fatal("pipe call in join()"); switch(fork()){ case -1:fatal("2nd fork call in join()"); case 0: dup2(p[1],1); close(p[0]); close(p[1]); execute_cmd(cmdlist[0]); fatal("1st execvp call in join()"); default: dup2(p[0],0); close(p[0]); close(p[1]); execute_cmd(cmdlist[1]); fatal("2nd execvp call in join()"); }}/* ************************************* * Link three child/grandchild processes * one by one with two pipes. * * ************************************/int join2(){ int status,p1[2],p2[2]; /*Test the double pipe.*/ if(dpipe_test()==0) return 0; /* Grandparent process */ switch(fork()){ case -1:fatal("1st fork call"); case 0:break; default: wait(&status); return status; } /* Parent process.Run the last command.*/ if(pipe(p1)<0) fatal ("pipe call"); /*make a pipe.*/ switch(fork()){ case -1:fatal("2nd fork call"); case 0:break; default: dup2(p1[0],0); close(p1[0]); close(p1[1]); execute_cmd(cmdlist[2]); fatal("1st exec call"); } /* Try to make a new pipe.*/ if(pipe(p2)<0) fatal("pipe call"); /* Child process.Run the second command.*/ switch(fork()){ case -1:fatal("3th fork call"); case 0:break; default: dup2(p1[1],1); dup2(p2[0],0); close(p1[0]); close(p1[1]); close(p2[0]); close(p2[1]); execute_cmd(cmdlist[1]); fatal("2nd exec call"); } /* Grandchild process.Run the first command.*/ dup2(p2[1],1); close(p2[0]); close(p2[1]); execute_cmd(cmdlist[0]); fatal("3th exec call");} |
