Доброго времени суток! Есть небольшая программка. Вот ее исходник: | Код |
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#define MAXLINE 256
#define MAXPATH 256
#define MAXARGS 25
#define HASHSIZE 101
struct hashList {
struct hashList *next;
char *szCommand;
char *szFullPath;
};
static struct hashList *hashTable[HASHSIZE];
/* hash: form hash value for a command name */
unsigned hash(char *szCommand) {
int i=0, sum=0;
while(szCommand[i]) sum += szCommand[i++];
return sum % HASHSIZE;
}
/* hashFind: find command in hash table */
struct hashList *hashFind(char *szCommand) {
struct hashList *hp;
for(hp=hashTable[hash(szCommand)]; hp !=NULL; hp=hp->next)
if(strcmp(szCommand, hp->szCommand)==0) return hp;
return NULL; /* not found */
}
/* hashInsert: insert command and path in hash table */
struct hashList *hashInsert(char *szCommand, char *szFullPath) {
struct hashList *hp;
unsigned hashVal;
if((hp=hashFind(szCommand))==NULL) { /* not found */
hp=(struct hashList *)malloc(sizeof(*hp));
if(hp==NULL || (hp->szCommand = strdup(szCommand))==NULL
|| (hp->szFullPath = strdup(szFullPath))==NULL)
return NULL; /* Couldn't add the hash entry */
hashVal=hash(szCommand);
hp->next = hashTable[hashVal];
hashTable[hashVal]=hp;
}
return hp;
}
int main() {
const char *szPrompt = "msh> ";
char sInputBuf[MAXLINE];
char szFilePath[MAXPATH];
char *szDirPath;
char *szEnvPath=strdup(getenv("PATH"));
char *szCommand;
char *szArgs[MAXARGS];
DIR *dp;
struct dirent *d;
struct stat statBuf;
struct hashList *hp;
int i, status;
pid_t pid;
/* Scan PATH directories and add commands to hash table */
szDirPath=strtok(szEnvPath, ":");
while( szDirPath != NULL ) {
if((dp=opendir(szDirPath)) != NULL) {
while((d=readdir(dp))) {
if(d->d_ino != 0) {
strcpy(szFilePath, szDirPath);
strcat(szFilePath, "/");
strcat(szFilePath, d->d_name);
if(lstat(szFilePath, &statBuf) >= 0)
if(S_ISREG(statBuf.st_mode) && access(szFilePath,X_OK)==0)
hashInsert(d->d_name, szFilePath);
}
}
closedir(dp);
}
szDirPath = strtok(NULL, ":");
}
/* Get commands until Ctrl-D */
fputs(szPrompt, stdout); /* Prompt for command input */
while( fgets(sInputBuf, MAXLINE, stdin) != NULL ) {
/* Parse command line arguments */
szArgs[i=0] = strtok(sInputBuf, " \n");
while( i<MAXARGS && szArgs[i] != NULL ) szArgs[++i] = strtok(NULL, " \n");
if(szArgs[0] == NULL) szCommand = NULL;
else { /* Find path to command */
if(strchr(szArgs[0], '/') != NULL) szCommand=szArgs[0]; /* path given */
else { /* look up full command path in hash table */
if((hp=hashFind(szArgs[0])) != NULL) {
szCommand=hp->szFullPath;
} else {
szCommand = NULL;
fprintf(stderr, "%s: command not found.\n", szArgs[0]);
}
}
}
if(szCommand != NULL) {
/* Fork and execute command, wait for completion */
if((pid=fork()) < 0) { /* Error */
perror("Error in fork()");
exit(1);
} else if(pid == 0) { /* run command in child process */
execv(szCommand, szArgs);
/* Reach here only if the command would not exec */
perror(szCommand);
exit(1);
}
if(waitpid(pid, &status, 0) == -1) {
perror("Error in waitpid()");
exit(1);
}
}
fputs(szPrompt, stdout); /* Prompt for next command */
}
fputc('\n', stdout);
return 0;
}
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Подскажите, пожалуйста, кусок кода, который нужно сюда добавить, чтобы этот shell реагировал на команду, например, exit. К примеру, запускаешь shell, вводишь exit и работа shell'а прерывается. |
Добавление команд в shell, добавление команд в shell 
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