Add pipes to shell, add wc

src/user/app/shell/shell.c

@@ -3,15 +3,15 @@
 #include "src/lib/util.h"
 #include "src/user/syscall.h"
 
-static void help(uint8_t argc, char **argv);
-static void cd(uint8_t argc, char **argv);
+static void help(uint8_t argc, char **argv, uint64_t stdin, uint64_t stdout);
+static void cd(uint8_t argc, char **argv, uint64_t stdin, uint64_t stdout);
 
 #define PATH "/bin/"
 
-#define PRINT_S(s) write(1, s, sizeof(s) - 1);
-#define PRINT_D(s) write(1, s, string_length(s));
+#define PRINT_S(o, s) write(o, s, sizeof(s) - 1);
+#define PRINT_D(o, s) write(o, s, string_length(s));
 
-typedef void (*app_t)(uint8_t argc, char **argv);
+typedef void (*app_t)(uint8_t argc, char **argv, uint64_t stdin, uint64_t stdout);
 
 typedef struct {
   const char *name;
@@ -23,27 +23,27 @@ static app_entry_t builtins[] = {
     {"cd", cd},
 };
 
-static void help(uint8_t argc, __attribute__((unused)) char **argv) {
+static void help(uint8_t argc, __attribute__((unused)) char **argv, __attribute__((unused)) uint64_t stdin, uint64_t stdout) {
   if (argc > 1) {
-    PRINT_S("help: expects no arguments");
+    PRINT_S(stdout, "help: expects no arguments\n");
     return;
   }
 
-  PRINT_S("Available commands:\n");
+  PRINT_S(stdout, "Available commands:\n");
   for (uint64_t i = 0; i < sizeof(builtins) / sizeof(app_entry_t); i++) {
-    PRINT_D(builtins[i].name);
-    PRINT_S("\n");
+    PRINT_D(stdout, builtins[i].name);
+    PRINT_S(stdout, "\n");
   }
 }
 
-static void cd(uint8_t argc, char **argv) {
+static void cd(uint8_t argc, char **argv, __attribute__((unused)) uint64_t stdin, uint64_t stdout) {
   if (argc != 2) {
-    PRINT_S("cd: requires a single path\n");
+    PRINT_S(stdout, "cd: requires a single path\n");
     return;
   }
 
   if (chdir(argv[1]) == (uint64_t)-1) {
-    PRINT_S("cd: path does not exist\n");
+    PRINT_S(stdout, "cd: path does not exist\n");
   }
 }
 
@@ -53,16 +53,23 @@ static void print_prompt() {
   char *components[16];
   uint8_t cl = string_split(path, '/', 16, components);
 
-  PRINT_S("[")
-  PRINT_D(pl == 1 ? "/" : components[cl - 1]);
-  PRINT_S("]$ ");
+  PRINT_S(1, "[")
+  PRINT_D(1, pl == 1 ? "/" : components[cl - 1]);
+  PRINT_S(1, "]$ ");
+}
+
+static void free_fds(uint64_t *fds, uint8_t fds_count) {
+  for (uint8_t i = 0; i < fds_count; i++) {
+    close(fds[i]);
+  }
+}
+
+static void kill_pids(__attribute__((unused)) uint64_t *pids, __attribute__((unused)) uint8_t pid_count) {
+  // TODO.
 }
 
 static void execute(char *command) {
-  char *argv[16];
-  uint8_t argc = (uint8_t)string_split(command, ' ', 16, argv);
-
-  PRINT_S("\n");
+  PRINT_S(1, "\n");
 
   if (string_equal(command, "^C")) {
     print_prompt();
@@ -71,34 +78,85 @@ static void execute(char *command) {
 
   if (string_equal(command, "^D")) {
     exit(EXIT_CODE_OK);
+    return;
   }
 
-  uint8_t i;
-  for (i = 0; i < sizeof(builtins) / sizeof(app_entry_t); i++) {
-    if (string_equal(argv[0], builtins[i].name)) {
-      builtins[i].app(argc, argv);
-      break;
-    }
-  }
-  if (i == sizeof(builtins) / sizeof(app_entry_t)) {
-    uint64_t size = sizeof(PATH) + string_length(argv[0]) + 1;
-    char *path = memory_allocate(size);
-    memory_copy(PATH, sizeof(PATH), path);
-    memory_copy(argv[0], size - sizeof(PATH), path + sizeof(PATH) - 1);
-    uint64_t pid = spawn(path, argc, (const char **)argv);
-    memory_free(path);
+  char *subcommands[16];
+  uint8_t subcommands_count = (uint8_t)string_split(command, '|', 16, subcommands);
 
-    if (pid == EXIT_CODE_NOT_FOUND) {
-      PRINT_S("shell: program not found\n");
-    } else {
-      waitpid(pid);
+  uint64_t fds[32];
+  uint8_t fds_count = 0;
+
+  uint64_t pids[16];
+  uint8_t pids_count = 0;
+
+  for (uint8_t i = 0; i < subcommands_count; i++) {
+    string_trim(subcommands[i], ' ', &subcommands[i]);
+
+    char *argv[16];
+    uint8_t argc = (uint8_t)string_split(subcommands[i], ' ', 16, argv);
+
+    uint64_t stdin = 0;
+    uint64_t stdout = 1;
+
+    if (i > 0) {
+      stdin = fds[fds_count - 1];
+    }
+    if (i < subcommands_count - 1) {
+      if (pipe(&fds[fds_count], &fds[fds_count + 1]) == (uint64_t)-1) {
+        kill_pids(pids, pids_count);
+        free_fds(fds, fds_count);
+        print_prompt();
+        return;
+      }
+      fds_count += 2;
+      stdout = fds[fds_count - 2];
+    }
+
+    uint8_t j;
+    for (j = 0; j < sizeof(builtins) / sizeof(app_entry_t); j++) {
+      if (string_equal(argv[0], builtins[j].name)) {
+        builtins[j].app(argc, argv, stdin, stdout);
+        pids[pids_count++] = 0;
+        break;
+      }
+    }
+    if (j == sizeof(builtins) / sizeof(app_entry_t)) {
+      uint64_t size = sizeof(PATH) + string_length(argv[0]) + 1;
+      char *path = memory_allocate(size);
+      memory_copy(PATH, sizeof(PATH), path);
+      memory_copy(argv[0], size - sizeof(PATH), path + sizeof(PATH) - 1);
+      uint64_t pid = spawn(path, argc, (const char **)argv, stdin, stdout);
+      memory_free(path);
+
+      if (pid == (uint64_t)-1) {
+        kill_pids(pids, pids_count);
+        free_fds(fds, fds_count);
+        print_prompt();
+        return;
+      } else {
+        pids[pids_count++] = pid;
+      }
     }
   }
+
+  for (uint8_t i = 0; i < pids_count; i++) {
+    if (pids[i]) {
+      waitpid(pids[i]);
+    }
+    if (i > 0) {
+      close(fds[(i - 1) * 2 + 1]);
+    }
+    if (i < pids_count - 1) {
+      close(fds[i * 2]);
+    }
+  }
+
   print_prompt();
 }
 
 uint64_t main() {
-  PRINT_D("Welcome to FreywarOS v" VERSION "!\n\n");
+  PRINT_D(1, "Welcome to FreywarOS v" VERSION "!\n\n");
 
   print_prompt();