HW: Task 1234.

task1/examples/10_exec_pipes.c

@@ -26,27 +26,42 @@ void seq_pipe(char ***cmd)
   int   fd_in = 0;
   int   i = 0;
 
-  while (cmd[i] != NULL) {
+  while (cmd[i] != NULL)
+  {
     pipe(p);
+
     printf("New used pipe descriptors: %d %d\n",p[0],p[1]);
     printf("Input descriptor for current child process: %d\n", fd_in);
-    if ((pid = fork()) == -1) {
+
+    if ((pid = fork()) == -1) 
+    {
           exit(1);
-    } else if (pid == 0) {
+    } 
+    else if (pid == 0) 
+    {
         if (i > 0)
-          dup2(fd_in, 0); //stdin <- read from fd_in (dup / dup2(int oldfd, int newfd) newfd <--copy( oldfd ) )
+          dup2(fd_in,  0); //d) newfd <--copy( oldfd ) )
+
+        fprintf(stdout, "%d\n", fd_in);
+
         if (cmd[i+1] != NULL)
           dup2(p[1], 1); //stdout -> write to pipe
+
         close(p[0]);
+
         execvp((cmd)[i][0], cmd[i]);
         exit(2);
-    } else {
+    } 
+    else
+    {
       wait(NULL);
       close(p[1]);
+
       if (i>0)
         close(fd_in); // old pipe from previous step is not used further, and can be destroyed
+
       fd_in = p[0]; //fd_in <--read from pipe
-        i++;
+      i++;
     }
 }
   return;
@@ -56,8 +71,7 @@ int main()
 {
   char *ls[] = {"/bin/ls","-ltr",".", NULL};
   char *grep1[] = {"grep","rw",NULL};
-  char *grep2[] = {"grep","1", NULL};
+  char **cmd[] = {ls, grep1, NULL};
+  seq_pipe(cmd);  char *grep2[] = {"grep","1", NULL};
   char *grep3[] = {"grep", "89", NULL};
-  char **cmd[] = {ls, grep1, grep2, grep3, NULL};
-  seq_pipe(cmd);
 }

task1/examples/beta.c

@@ -0,0 +1,43 @@
+/* Небольшое улучшение примера 10, которое позволяет держать не более 2 пайпов открытыми
+Пайп пересоздается n-1 раз, но старые пайпы закрываются за ненадобностью. На одном пайпе я не вижу смысла делать, так как ввод и вывод перемешаются 
+Для того, чтобы убедиться, посмотрите вывод используемых дескрипторов (строка 22-23).
+У меня это:
+New used pipe descriptors: 3 4
+Input descriptor for current child process: 0
+New used pipe descriptors: 4 5
+Input descriptor for current child process: 3
+New used pipe descriptors: 3 5
+Input descriptor for current child process: 4
+New used pipe descriptors: 4 5
+Input descriptor for current child process: 3
+*/
+
+
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <stdio.h>
+
+void seq_pipe(char ***cmd)
+{
+    int   pipe_fd[2] = {-1, -1};
+    pid_t pid   ;
+    int   fd_in = 0;
+    int   i = 0;
+
+
+
+
+    return;
+}
+
+int main()
+{
+  char *ls[] = {"/bin/ls","-ltr",".", NULL};
+  char *grep1[] = {"grep","rw",NULL};
+  char *grep2[] = {"grep","1", NULL};
+  char *grep3[] = {"grep", "89", NULL};
+  char **cmd[] = {ls, grep1, grep2, grep3, NULL};
+  seq_pipe(cmd);
+}

task1/homework/main.c

@@ -0,0 +1,31 @@
+#include "pcmd.h"
+#include "tokenizator.h"
+
+int main()
+{
+    fprintf(stdout, "BASH:(0)_(0): ");
+
+    struct CmdTokens s_cmd = {};
+
+    if (constructTokens(&s_cmd) == CONSTRUCT_ERR)
+    {
+        fprintf(stderr, "ERROR: Unable to construct token structure\n");
+        destructEmptyTokens(&s_cmd);
+        return CONSTRUCT_ERR;
+    }
+
+    if (tokenizator(&s_cmd) == MAX_NUM_TOKENS_ERR)
+    {
+        fprintf(stderr, "ERROR: Maximum number of commands exceeded\n");
+        destructEmptyTokens(&s_cmd);
+        return MAX_NUM_TOKENS_ERR;
+    }
+
+    run(&s_cmd);
+
+    destructTokens(&s_cmd);
+
+    return 0;
+}
+
+

task1/homework/makefile

@@ -0,0 +1,4 @@
+CC=gcc
+
+all:
+	gcc main.c pcmd.c tokenizator.c -D _DEBUG -ggdb3 -O0 -Wall -Wextra -Waggressive-loop-optimizations -Wmissing-declarations -Wcast-align -Wcast-qual -Wchar-subscripts -Wconversion -Wempty-body -Wfloat-equal -Wformat-nonliteral -Wformat-security -Wformat-signedness -Wformat=2 -Winline -Wlogical-op -Wopenmp-simd -Wpacked -Wpointer-arith -Winit-self -Wredundant-decls -Wshadow -Wsign-conversion -Wstrict-overflow=2 -Wsuggest-attribute=noreturn -Wsuggest-final-methods -Wsuggest-final-types -Wswitch-default -Wswitch-enum -Wsync-nand -Wundef -Wunreachable-code -Wunused -Wvariadic-macros -Wno-missing-field-initializers -Wno-narrowing -Wno-varargs -Wstack-protector -fcheck-new -fstack-protector -fstrict-overflow -flto-odr-type-merging -fno-omit-frame-pointer -pie -fPIE -fsanitize=address,alignment,bool,bounds,enum,float-cast-overflow,float-divide-by-zero,integer-divide-by-zero,leak,nonnull-attribute,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,undefined,unreachable,vla-bound,vptr

task1/homework/pcmd.c

@@ -0,0 +1,52 @@
+#include "pcmd.h"
+
+
+void run(struct CmdTokens* s_commands)
+{
+    // example /bin/ls -ltr . | grep rw
+
+    int   pipeFd[2] = {-1, -1};
+    pid_t pid       = -1;
+    int   fd_in     = -1;
+
+    for (size_t counter = 0; counter < s_commands->pipelineCapacity + 1; counter++)
+    {
+        pipe(pipeFd);
+
+        if ((pid = fork()) == -1)
+        {
+            fprintf(stderr, "ERROR:Unable to create process. A system-imposed limit on the number of threads was encountered\n");
+        }
+        else if (pid == 0)
+        {
+            if (counter > 0)
+                dup2(fd_in, 0); //stdin
+
+            if (counter != s_commands->pipelineCapacity) dup2(pipeFd[1], 1); //stdout
+
+            close(pipeFd[0]);
+
+            if (execvp(s_commands->flags[counter][0], s_commands->flags[counter]) == - 1)
+            {
+                fprintf(stderr, "ERROR: execvp error, check errno; Command not found.\n");
+            }
+
+            exit(-1);
+        }
+        else
+        {
+            int status = 0;
+
+            waitpid(pid, &status, WNOHANG);
+
+            s_commands->exitStatus[counter] = WEXITSTATUS(status);
+
+            close(pipeFd[1]);
+
+            if (counter > 0) close(fd_in);
+
+            fd_in = pipeFd[0];
+        }   
+    }    
+    return;
+}

task1/homework/pcmd.h

@@ -0,0 +1,16 @@
+#ifndef PCMD_H
+#define PCMD_H
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+
+#include "tokenizator.h"
+
+void run(struct CmdTokens* s_commads);
+
+
+
+#endif