下面是代码,有兴趣的试试。 .doc

下面是代码，有兴趣的试试。 [code:1:f33df78f6c] #include?unistd.h #include?stdio.h #include?stdlib.h #include?sys/wait.h #include?string.h #include?errno.h #define?SHELL_NAME?sh1 #define?PROMPT_ENVIRONMENT_VARIABLE?PROMPT char?*prompt; int爉ain(int燼rgc,燾har?*argv)?{ char燾md[80]; int爏tatval; 牋 /*燚etermine爌rompt爒alue.?/ if?(prompt?爂etenv(PROMPT_ENVIRONMENT_VARIABLE))?=燦ULL) prompt?燬HELL_NAME?:; /*燩rocess燾ommands爑ntil爀xit,爋r燿eath燽y爏ignal.?/ while?1)?{ /*燩rompt燼nd爎ead燼燾ommand.?/ printf(prompt); gets(cmd); /*燩rocess燽uilt-in燾ommands.?/ if(strcasecmp(cmd,?exit)?=?) break; /*燩rocess爊on-built-in燾ommands.?/ if(fork()?=?)爗 execlp(cmd,燾md,燦ULL); fprintf(stderr,?%s:燛xec?s爁ailed:?s\n,燼rgv[0],?cmd,爏trerror(errno)); exit(1); }?wait(statval); if(WIFEXITED(statval))?{ if(WEXITSTATUS(statval)) { fprintf(stderr, %s:燾hild爀xited爓ith爏tatus?d.\n, argv[0],燱EXITSTATUS(statval)); } }爀lse爗 fprintf(stderr,?%s:燾hild燿ied爑nexpectedly.\n,?argv[0]); } } } [/code:1:f33df78f6c] /jh/23/63236.html ?蓝色键盘 回复于：2003-05-07 18:59:05 这是对上面代码做了改进以后的版本。 [code:1:7745bfe68e] #include?unistd.h #include?stdio.h #include?stdlib.h #include?sys/wait.h #include?errno.h char?*parse_cmd(char?*cmd,?char?**argarr,?int?*narg)?{ enum?states?{?S_START,燬_IN_TOKEN,燬_IN_QUOTES,燬_SEintMI爙; int燼rgc=0; //燗rg燾ount int爈oop=1; //燣oop燾ontrol enum爏tates爏tate?燬_START; //燙urrent爏tate. int爈astch; //燣ast燾haracter爀ncountered. 牋?while?loop)爗 switch?state)爗 case燬_START: if?*cmd?=?)爗 *argarr++?燾md??; ++argc; state?燬_IN_QUOTES; } else爄f?*cmd?=?爘|?cmd?=?;) loop??; else爄f?*cmd?=??) *cmd??; else爗 *argarr++?燾md; ++argc; state?燬_IN_TOKEN; } break; case燬_IN_TOKEN: if?*cmd?=?爘|?cmd?=?;) loop??; else爄f?*cmd?=??)爗 *cmd=0; state=S_START; } break; case燬_IN_QUOTES: if?*cmd?=?) loop??; else爄f?*cmd?=?)爗 *cmd??; state?燬_STA