Add command execution with redirection

Expose command execution with pipes to stdin, stdout and stderr.

app/src/command.h

@@ -24,11 +24,13 @@
 # define PROCESS_NONE NULL
   typedef HANDLE process_t;
   typedef DWORD exit_code_t;
+  typedef HANDLE pipe_t;
 #else
 # include <sys/types.h>
 # define PROCESS_NONE -1
   typedef pid_t process_t;
   typedef int exit_code_t;
+  typedef int pipe_t;
 #endif
 # define NO_EXIT_CODE -1
 
@@ -39,6 +41,8 @@ enum process_result {
 };
 
 enum process_result cmd_execute(const char *path, const char *const argv[], process_t *process);
+enum process_result cmd_execute_redirect(const char *path, const char *const argv[], process_t *process,
+                                         pipe_t *pipe_stdin, pipe_t *pipe_stdout, pipe_t *pipe_stderr);
 SDL_bool cmd_terminate(process_t pid);
 SDL_bool cmd_simple_wait(process_t pid, exit_code_t *exit_code);
 
@@ -55,4 +59,7 @@ process_t adb_remove_path(const char *serial, const char *path);
 // automatically log process errors with the provided process name
 SDL_bool process_check_success(process_t process, const char *name);
 
+int read_pipe(pipe_t pipe, char *data, size_t len);
+void close_pipe(pipe_t pipe);
+
 #endif

app/src/sys/unix/command.c

@@ -1,5 +1,6 @@
 #include "command.h"
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -9,65 +10,151 @@
 #include <unistd.h>
 #include "log.h"
 
-enum process_result cmd_execute(const char *path, const char *const argv[], pid_t *pid) {
+enum process_result cmd_execute_redirect(const char *path, const char *const argv[], pid_t *pid,
-    int fd[2];
+                                         int *pipe_stdin, int *pipe_stdout, int *pipe_stderr) {
+    int in[2];
+    int out[2];
+    int err[2];
+    int internal[2]; // communication between parent and children
 
-    if (pipe(fd) == -1) {
+    if (pipe(internal) == -1) {
         perror("pipe");
         return PROCESS_ERROR_GENERIC;
     }
-
+    if (pipe_stdin) {
-    enum process_result ret = PROCESS_SUCCESS;
+        if (pipe(in) == -1) {
+            perror("pipe");
+            close(internal[0]);
+            close(internal[1]);
+            return PROCESS_ERROR_GENERIC;
+        }
+    }
+    if (pipe_stdout) {
+        if (pipe(out) == -1) {
+            perror("pipe");
+            // clean up
+            if (pipe_stdin) {
+                close(in[0]);
+                close(in[1]);
+            }
+            close(internal[0]);
+            close(internal[1]);
+            return PROCESS_ERROR_GENERIC;
+        }
+    }
+    if (pipe_stderr) {
+        if (pipe(err) == -1) {
+            perror("pipe");
+            // clean up
+            if (pipe_stdout) {
+                close(out[0]);
+                close(out[1]);
+            }
+            if (pipe_stdin) {
+                close(in[0]);
+                close(in[1]);
+            }
+            close(internal[0]);
+            close(internal[1]);
+            return PROCESS_ERROR_GENERIC;
+        }
+    }
 
     *pid = fork();
     if (*pid == -1) {
         perror("fork");
-        ret = PROCESS_ERROR_GENERIC;
+        // clean up
-        goto end;
+        if (pipe_stderr) {
+            close(err[0]);
+            close(err[1]);
+        }
+        if (pipe_stdout) {
+            close(out[0]);
+            close(out[1]);
+        }
+        if (pipe_stdin) {
+            close(in[0]);
+            close(in[1]);
+        }
+        close(internal[0]);
+        close(internal[1]);
+        return PROCESS_ERROR_GENERIC;
     }
 
-    if (*pid > 0) {
+    if (*pid == 0) {
-        // parent close write side
+        if (pipe_stdin) {
-        close(fd[1]);
+            if (in[0] != STDIN_FILENO) {
-        fd[1] = -1;
+                dup2(in[0], STDIN_FILENO);
-        // wait for EOF or receive errno from child
+                close(in[0]);
-        if (read(fd[0], &ret, sizeof(ret)) == -1) {
-            perror("read");
-            ret = PROCESS_ERROR_GENERIC;
-            goto end;
-        }
-    } else if (*pid == 0) {
-        // child close read side
-        close(fd[0]);
-        if (fcntl(fd[1], F_SETFD, FD_CLOEXEC) == 0) {
-            execvp(path, (char *const *)argv);
-            if (errno == ENOENT) {
-                ret = PROCESS_ERROR_MISSING_BINARY;
-            } else {
-                ret = PROCESS_ERROR_GENERIC;
             }
+            close(in[1]);
+        }
+        if (pipe_stdout) {
+            if (out[1] != STDOUT_FILENO) {
+                dup2(out[1], STDOUT_FILENO);
+                close(out[1]);
+            }
+            close(out[0]);
+        }
+        if (pipe_stderr) {
+            if (err[1] != STDERR_FILENO) {
+                dup2(err[1], STDERR_FILENO);
+                close(err[1]);
+            }
+            close(err[0]);
+        }
+        close(internal[0]);
+        enum process_result err;
+        if (fcntl(internal[1], F_SETFD, FD_CLOEXEC) == 0) {
+            execvp(path, (char *const *)argv);
             perror("exec");
+            err = errno == ENOENT ? PROCESS_ERROR_MISSING_BINARY
+                                  : PROCESS_ERROR_GENERIC;
         } else {
             perror("fcntl");
-            ret = PROCESS_ERROR_GENERIC;
+            err = PROCESS_ERROR_GENERIC;
         }
-        // send ret to the parent
+        printf("==> %d\n",(int)err);
-        if (write(fd[1], &ret, sizeof(ret)) == -1) {
+        // send err to the parent
+        if (write(internal[1], &err, sizeof(err)) == -1) {
             perror("write");
         }
-        // close write side before exiting
+        close(internal[1]);
-        close(fd[1]);
         _exit(1);
     }
 
-end:
+    /* parent */
-    if (fd[0] != -1) {
+    assert(*pid > 0);
-        close(fd[0]);
+
+    close(internal[1]);
+
+    enum process_result res = PROCESS_SUCCESS;
+    // wait for EOF or receive err from child
+    if (read(internal[0], &res, sizeof(res)) == -1) {
+        perror("read");
+        res = PROCESS_ERROR_GENERIC;
     }
-    if (fd[1] != -1) {
+
-        close(fd[1]);
+    close(internal[0]);
+
+    if (pipe_stdin) {
+        close(in[0]);
+        *pipe_stdin = in[1];
     }
-    return ret;
+    if (pipe_stdout) {
+        *pipe_stdout = out[0];
+        close(out[1]);
+    }
+    if (pipe_stderr) {
+        *pipe_stderr = err[0];
+        close(err[1]);
+    }
+
+    return res;
+}
+
+enum process_result cmd_execute(const char *path, const char *const argv[], pid_t *pid) {
+    return cmd_execute_redirect(path, argv, pid, NULL, NULL, NULL);
 }
 
 SDL_bool cmd_terminate(pid_t pid) {
@@ -92,3 +179,13 @@ SDL_bool cmd_simple_wait(pid_t pid, int *exit_code) {
     }
     return !code;
 }
+
+int read_pipe(int pipe, char *data, size_t len) {
+    return read(pipe, data, len);
+}
+
+void close_pipe(int pipe) {
+    if (close(pipe)) {
+        perror("close pipe");
+    }
+}

app/src/sys/win/command.c

@@ -17,15 +17,68 @@ static int build_cmd(char *cmd, size_t len, const char *const argv[]) {
     return 0;
 }
 
-enum process_result cmd_execute(const char *path, const char *const argv[], HANDLE *handle) {
+enum process_result cmd_execute_redirect(const char *path, const char *const argv[], HANDLE *handle,
+                                          HANDLE *pipe_stdin, HANDLE *pipe_stdout, HANDLE *pipe_stderr) {
+    SECURITY_ATTRIBUTES sa;
+    sa.nLength = sizeof(SECURITY_ATTRIBUTES);
+    sa.lpSecurityDescriptor = NULL;
+    sa.bInheritHandle = TRUE;
+
+    HANDLE stdin_read_handle;
+    HANDLE stdout_write_handle;
+    HANDLE stderr_write_handle;
+    if (pipe_stdin) {
+        if (!CreatePipe(&stdin_read_handle, pipe_stdin, &sa, 0)) {
+             perror("pipe");
+             return PROCESS_ERROR_GENERIC;
+        }
+    }
+    if (pipe_stdout) {
+        if (!CreatePipe(pipe_stdout, &stdout_write_handle, &sa, 0)) {
+             perror("pipe");
+             // clean up
+             if (pipe_stdin) {
+                CloseHandle(&stdin_read_handle);
+                CloseHandle(pipe_stdin);
+             }
+             return PROCESS_ERROR_GENERIC;
+        }
+    }
+    if (pipe_stderr) {
+        if (!CreatePipe(pipe_stderr, &stderr_write_handle, &sa, 0)) {
+            perror("pipe");
+            // clean up
+             if (pipe_stdin) {
+                CloseHandle(&stdin_read_handle);
+                CloseHandle(pipe_stdin);
+             }
+            if (pipe_stdout) {
+                CloseHandle(pipe_stdout);
+                CloseHandle(&stdout_write_handle);
+            }
+            return PROCESS_ERROR_GENERIC;
+        }
+    }
+
     STARTUPINFO si;
     PROCESS_INFORMATION pi;
     memset(&si, 0, sizeof(si));
     si.cb = sizeof(si);
+    if (pipe_stdin || pipe_stdout || pipe_stderr) {
+        si.dwFlags = STARTF_USESTDHANDLES;
+        if (pipe_stdin) {
+            si.hStdInput = stdin_read_handle;
+        }
+        if (pipe_stdout) {
+            si.hStdOutput = stdout_write_handle;
+        }
+        if (pipe_stderr) {
+            si.hStdError = stderr_write_handle;
+        }
+    }
 
     char cmd[256];
     if (build_cmd(cmd, sizeof(cmd), argv)) {
-        *handle = NULL;
         return PROCESS_ERROR_GENERIC;
     }
 
@@ -46,6 +99,10 @@ enum process_result cmd_execute(const char *path, const char *const argv[], HAND
     return PROCESS_SUCCESS;
 }
 
+enum process_result cmd_execute(const char *path, const char *const argv[], HANDLE *handle) {
+    return cmd_execute_redirect(path, argv, handle, NULL, NULL, NULL);
+}
+
 SDL_bool cmd_terminate(HANDLE handle) {
     return TerminateProcess(handle, 1) && CloseHandle(handle);
 }