int main(int argc, char **argv)
{
int cas;
int cur;
scanf("%d", &num_case);
getchar();
gets(str);
for (cas = 0; cas < num_case; cas++)
{
memset(mem, 0, sizeof(mem));
memset(reg, 0, sizeof(reg));
cur = 0;
while (gets(str))
{
if (!(strlen(str)))
{
break;
}
mem[cur++] = atoi(str);
}
do_exe();
printf("%d\n", count);
if (cas < num_case - 1)
{
printf("\n");
}
}
return 0;
}
void do_exe (int no_cmd,char * * * argv_list, int * argc_list, int index)
{
int pid,status,new_index = index+1;
int fds[2];
int i,t;
if(index == no_cmd)
return;
if(pipe(fds) <0)
{
perror("pipe error");
exit(1);
}
pid = fork();
if (pid == -1)
{
perror ("fork error\n");
exit(1);
}
else if (pid == 0)
{
//child process...
if(dup2(fds[1],1) <0)
{
perror("dup2 error\n");
exit(1);
}
close(fds[0]);
if(index ==0)
{
int fd,k,fl=0;
char ** cmd;
// for first command check for <
i=0;
for(t=0;t<=argc_list[i];t++)
{ char * tt=NULL;
tt = strchr(argv_list[i][t],'<');
//if '<' symbol found
if(tt != NULL)
{ //perror("< found");
char * file_name;
if(strlen(argv_list[i][t]) != 1)
{ file_name = (char*)malloc(sizeof(char)*strlen(tt));
strcpy(file_name,&tt[1]);
}
else
{ file_name = (char*)malloc(sizeof(char)*(strlen(argv_list[i][t+1])+1));
strcpy(file_name,argv_list[i][t+1]);
}
printf("%s", file_name);
fflush(stdout);
fd = open(file_name,O_RDONLY);
if(fd <0 )
{ perror("fd fails");}
//dup2(0,temp_stdin);
if(dup2(fd,0) != 0)
{
perror("dup2- file rediraction :");
exit(1);
}
cmd = (char**)calloc(t+1,sizeof(char*));
for(k =0; k<t ; k++)
{
cmd[k] = (char*) calloc(strlen(argv_list[i][k])+1,sizeof(char));
strcpy(cmd[k],argv_list[i][k]);
}
cmd[t] = 0;
fl=1;
break;
}
}
if(fl)
{
if(execvp(argv_list[0][0], cmd) <0)
{
perror("execvp error:");
exit(1);
}
}
else
{
if(execvp(argv_list[0][0], argv_list[0]) <0)
{
perror("execvp error:");
exit(1);
}
}
}
if(execvp(argv_list[index][0], argv_list[index]) < 0)
{
perror("execvp error:");
exit(1);
}
}
else
{
//parent process...
int fd1;
if(dup2(fds[0],0)<0)
{
perror("dup2 error\n");
exit(1);
}
close(fds[1]);
// Recurrsive executor call...
do_exe(no_cmd,argv_list,argc_list,new_index);
/*------------------------ This code is working for 2-3 command with > , but giving segmentation fault for larg string for inputs
// for last command check for >
if(new_index=no_cmd)
{
// for last command check for >
i=no_cmd;
for(t=0;t<=argc_list[i];t++)
{ char * tt=NULL;
tt = strchr(argv_list[i][t],'>');
//if '<' symbol found
if(tt != NULL)
{ char * file_name;
//perror("hhhh");
//strcpy(argv_list[i][t],NULL);
if(strlen(argv_list[i][t]) != 1)
{ file_name = (char*)malloc(sizeof(char)*strlen(tt));
strcpy(file_name,&tt[1]);
}
else
{ file_name = (char*)malloc(sizeof(char)*(strlen(argv_list[i][t+1])+1));
strcpy(file_name,argv_list[i][t+1]);
//strcpy(argv_list[i][t+1],NULL);
}
fd1 = open(file_name,O_CREAT|O_WRONLY, 0644);
//dup2(1,temp_stdout);
if(fd1 < 0 )
{ perror("fd1 : hi hi");}
if(dup2(fd1,1) != 1)
{
perror("dup2- file rediraction :");
exit(1);
}
cmd = (char**)calloc(t+1,sizeof(char*));
for(k =0; k<t ; k++)
{
cmd[k] = (char*) calloc(strlen(argv_list[i][k])+1,sizeof(char));
strcpy(cmd[k],argv_list[i][k]);
}
cmd[t] = 0;
fl =1;
break;
}
}
if (fl)
{
if(execvp(argv_list[new_index][0],cmd) <0)
{
perror("execvp error:");
exit(1);
}
}
else
{
if(execvp(argv_list[new_index][0], argv_list[new_index]) <0)
{
perror("execvp error:");
exit(1);
}
}
}*/
//-----------------------------------end of > logic
// for last command check for >
if(new_index=no_cmd)
{
}
if(execvp(argv_list[new_index][0], argv_list[new_index]) <0)
{
perror("execvp error:");
exit(1);
}
}
}
int cmd_executor(int no_cmd, char * * * argv_list, int * argc_list)
{
int i,t,fd,fd1,pid,status,k,fl=0;
int background_flag =0;
char * * cmd;
// for last command check for &
if(argv_list[no_cmd][argc_list[no_cmd]] == "&")
{
background_flag =1;
}
/////////////////////////////////////////////////////////////
pid = fork();
if(pid < 0 )
{ perror("fork failed...");
exit(1);
}
else if(pid == 0)
{
//perror("hi hi hi");
if(no_cmd == 0)
{
//perror("hi hi");
/*const int argc= argc_list[0]+1;
char * cmd[argc];
for(t =0; t<=argc ; t++)
{
strcpy(cmd[t],argv_list[0][t]);
}
cmd[t] = 0;
*/
// for last command check for >
i=no_cmd;
for(t=0;t<=argc_list[i];t++)
{ char * tt=NULL;
tt = strchr(argv_list[i][t],'>');
//if '<' symbol found
if(tt != NULL)
{ char * file_name;
//perror("hhhh");
//strcpy(argv_list[i][t],NULL);
if(strlen(argv_list[i][t]) != 1)
{ file_name = (char*)malloc(sizeof(char)*strlen(tt));
strcpy(file_name,&tt[1]);
}
else
{ file_name = (char*)malloc(sizeof(char)*(strlen(argv_list[i][t+1])+1));
strcpy(file_name,argv_list[i][t+1]);
//strcpy(argv_list[i][t+1],NULL);
}
fd1 = open(file_name,O_CREAT|O_WRONLY, 0644);
//dup2(1,temp_stdout);
if(fd1 < 0 )
{ perror("fd1 : hi hi");}
if(dup2(fd1,1) != 1)
{
perror("dup2- file rediraction :");
exit(1);
}
cmd = (char**)calloc(t+1,sizeof(char*));
for(k =0; k<t ; k++)
{
cmd[k] = (char*) calloc(strlen(argv_list[i][k])+1,sizeof(char));
strcpy(cmd[k],argv_list[i][k]);
}
cmd[t] = 0;
fl =1;
break;
}
}
// for first command check for <
i=0;
for(t=0;t<=argc_list[i];t++)
{ char * tt=NULL;
tt = strchr(argv_list[i][t],'<');
//if '<' symbol found
if(tt != NULL)
{ //perror("< found");
char * file_name;
if(strlen(argv_list[i][t]) != 1)
{ file_name = (char*)malloc(sizeof(char)*strlen(tt));
strcpy(file_name,&tt[1]);
}
else
{ file_name = (char*)malloc(sizeof(char)*(strlen(argv_list[i][t+1])+1));
strcpy(file_name,argv_list[i][t+1]);
}
printf("%s", file_name);
fflush(stdout);
fd = open(file_name,O_RDONLY);
if(fd <0 )
{ perror("fd fails");}
//dup2(0,temp_stdin);
if(dup2(fd,0) != 0)
{
perror("dup2- file rediraction :");
exit(1);
}
cmd = (char**)calloc(t+1,sizeof(char*));
for(k =0; k<t ; k++)
{
cmd[k] = (char*) calloc(strlen(argv_list[i][k])+1,sizeof(char));
strcpy(cmd[k],argv_list[i][k]);
}
cmd[t] = 0;
fl=1;
break;
}
}
if(fl)
{
if(execvp(argv_list[0][0], cmd) <0)
{
perror("execvp error:");
exit(1);
}
}
else
{
if(execvp(argv_list[0][0], argv_list[0]) <0)
{
perror("execvp error:");
exit(1);
}
}
}
else
{
//perror("hi hi hi");
// First time executor call with 0 index
do_exe(no_cmd,argv_list,argc_list,0);
}
}
else
{
if(!background_flag)
wait(&status);
}
return 0;
}
