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First off, this a homework assignment so most of the syntax in the code that I'm about to append to this thread is required by my professor. Anywho...I'm having trouble with the piping in my code. Here is what I have:
Everything compiles just fine, but for instance when the shell is running I type in "type hunt program5.c | sort" it is supposed to translate DOS commands into Unix commands(which it does correctly) but when I try to cat(or type is the DOS syntax..etc) my program called hunt and program5.c and then pipe it by sorting the two programs it gives me the following promptCode:#include <stdio.h> #include <string.h> #include <stdbool.h> #include <unistd.h> #include <sys/wait.h> #include <fcntl.h> #include <assert.h> int fg_id = 0; void sigchldHandler(int sig) { int status = 0; int pid = wait(&status); if (pid == fg_id) { fg_id = 0; } } int main() { char* dosCmd[] = {"exit", "dir", "md", "type", "sort", "del", "copy", ">", ">>", "&"}; char* unixCmd[] = {"exit", "ls", "mkdir", "cat", "sort", "rm", "cp", ">", ">>", "&"}; signal(SIGCHLD, sigchldHandler); while (1) { int args = 0; char* argv[10]; char* delimiter = " \n"; char command[80] = {0}; int redir = 0; int reder = 0; bool foreground = true; printf("terminal@piping> "); fgets(command, sizeof(command), stdin); if (command[0] == '\n') continue; // gather input tokens argv[args++] = strtok(command, delimiter); do { int z = 0; for(; (z < 10) && (strcmp(argv[args-1], dosCmd[z]) != 0); ++z); switch(z) { case 0: return 0; break; case 1: case 2: case 3: case 4: case 5: case 6: argv[args-1] = unixCmd[z]; break; case 7: reder = args-1; argv[args-1] = NULL; break; case 8: redir = args-1; argv[args-1] = NULL; break; case 9: foreground = false; argv[args-1] = NULL; break; } } while ((argv[args] = strtok(NULL, delimiter)) != NULL && (++args < 10)); if (args > 0) { int file_des[2]; int new_cid; pipe(file_des); if ((new_cid = fork()) == 0) { // child process usleep(10000); // delay for parent to setup semaphore for foreground processes close(file_des[1]); assert(dup2(file_des[0], 0) != -1); int file_ptr = 0; if (reder) { file_ptr = open(argv[reder+1], O_WRONLY | O_CREAT | O_TRUNC, 0666); } else if (redir) { file_ptr = open(argv[redir+1], O_WRONLY | O_APPEND, 0666); } if (file_des[1]) dup2(file_des[1], 1); execvp(argv[0], argv); close(file_des[0]); if (file_ptr) close(file_ptr); } else if (foreground) { fg_id = new_cid; while(fg_id) usleep(10000); // don't pound the CPU } } } return 0; }
When I type "type hunt" it displays my program hunt's source code just fine but once I try to pipe the programs it doesn't do as I expected. Any suggestions? My apologies if I didn't elaborate very well on my struggles.Code:terminal@piping> type hunt program5.c | sort #!/bin/csh # Chad Reynolds - CSC 60 - Section 1 set directoryCount = 0 set fileCount = 0 ### Test to see if no arguments get inputted on the command line if($#argv == 0)then echo Usage: Missing arguments, please re-execute hunt else while(1) foreach val (`ls`) if(-d $val) then ### If val is a directory then increment its value to see ### the total amount of directories searched @ directoryCount = $directoryCount + 1 ### Push back to the current directory and add to the stack pushd $val >> ~/dump pushd +1 >> ~/dump else if($val =~ $1) then ### Echo full path @ fileCount = $fileCount + 1 echo `pwd`/$val else if(-e $val) then ### Increment file count if val is a file @ fileCount = $fileCount + 1 endif ### End for end ### If directory or word count is greater than 1, ### then pop the directory off the stack if(`dirs | wc -w` > 1) then popd >> ~/dump else ### Else, the stack is complete, so output the file count, ### directory count, and delete temp file dump rm ~/dump echo Files Searched: $fileCount echo Directories Searched: $directoryCount ### Infinite loop, so a break statement is needed break endif ### End while end ### End if($#argv == 0)/Else endif #include <stdio.h> #include <string.h> #include <stdbool.h> #include <unistd.h> #include <signal.h> #include <stdlib.h> #include <sys/wait.h> #include <sys/file.h> #include <fcntl.h> #include <assert.h> int fg_id = 0; int pid = 0; int status = 0; int file_ptr = 0; int file_des[2]; void sigchldHandler(int sig) { pid = wait(&status); if (pid == fg_id) { fg_id = 0; } signal(SIGCHLD, sigchldHandler); } int main() { char* dosCmd[] = {"exit", "dir", "md", "type", "sort", "del", "copy", ">", ">>", "&", "|" }; char* unixCmd[] = {"exit", "ls", "mkdir", "cat", "sort", "rm", "cp", ">", ">>", "&", "|"}; signal(SIGCHLD, sigchldHandler); while (1) { int args = 0; char* argv[10]; char* delimiter = " \n"; char command[80] = {0}; int redir = 0; int reder = 0; bool foreground = true; printf("terminal@piping> "); fgets(command, sizeof(command), stdin); if (command[0] == '\n') continue; // gather input tokens argv[args++] = strtok(command, delimiter); do { int z = 0; for(; (z < 10) && (strcmp(argv[args-1], dosCmd[z]) != 0); ++z); switch(z) { case 0: return 0; break; case 1: case 2: case 3: case 4: case 5: case 6: argv[args-1] = unixCmd[z]; break; case 7: reder = args-1; argv[args-1] = NULL; break; case 8: redir = args-1; argv[args-1] = NULL; break; case 9: foreground = false; argv[args-1] = NULL; break; } }//end do while ((argv[args] = strtok(NULL, delimiter)) != NULL && (++args < 10)); if (args > 0) { int new_cid; pipe(file_des); if ((new_cid = fork()) == 0) { // child process usleep(10000); // delay for parent to setup semaphore for foreground processes close(file_des[1]); assert(dup2(file_des[0], 0) != -1); if (reder) { file_ptr = open(argv[reder+1], O_WRONLY | O_CREAT | O_TRUNC, 0666); } else if (redir) { file_ptr = open(argv[redir+1], O_WRONLY | O_APPEND, 0666); } if (file_des[1]) { dup2(file_des[1], 1); } execvp(argv[0], argv); close(file_des[0]); if (file_ptr) { close(file_ptr); } }//end if((new_cid = fork()) == 0) else if (foreground) { fg_id = new_cid; while(fg_id) usleep(10000); // don't pound the CPU } }//end if(args > 0) } return 0; } cat: |: No such file or directory cat: sort: No such file or directory terminal@piping>
