Add functionality for running external programs to the std lib

See lib/run_program.rs.

1 files changed, 96 insertions, 0 deletions

diff --git a/src/lib/run_program.rs b/src/lib/run_program.rs
new file mode 100644
index 00000000..bd9edbc8
--- /dev/null
+++ b/src/lib/run_program.rs
@@ -0,0 +1,96 @@
+import _str.sbuf;
+import _vec.vbuf;
+
+native "rust" mod rustrt {
+    fn rust_run_program(vbuf argv, int in_fd, int out_fd, int err_fd) -> int;
+}
+
+fn argvec(str prog, vec[str] args) -> vec[sbuf] {
+    auto argptrs = vec(_str.buf(prog));
+    for (str arg in args) {
+        argptrs = _vec.push[sbuf](argptrs, _str.buf(arg));
+    }
+    argptrs = _vec.push[sbuf](argptrs, 0 as sbuf);
+    ret argptrs;
+}
+
+impure fn run_program(str prog, vec[str] args) -> int {
+    auto pid = rustrt.rust_run_program(_vec.buf[sbuf](argvec(prog, args)),
+                                       0, 0, 0);
+    ret os.waitpid(pid);
+}
+
+type program =
+    state obj {
+        fn get_id() -> int;
+        fn input() -> io.writer;
+        fn output() -> io.reader;
+        impure fn close_input();
+        impure fn finish() -> int;
+    };
+
+impure fn start_program(str prog, vec[str] args) -> @program {
+    auto pipe_input = os.pipe();
+    auto pipe_output = os.pipe();
+    auto pid = rustrt.rust_run_program
+        (_vec.buf[sbuf](argvec(prog, args)),
+         pipe_input._0, pipe_output._1, 0);
+    if (pid == -1) {fail;}
+    os.libc.close(pipe_input._0);
+    os.libc.close(pipe_output._1);
+
+    state obj new_program(int pid,
+                          int in_fd,
+                          os.libc.FILE out_file,
+                          mutable bool finished) {
+        fn get_id() -> int {ret pid;}
+        fn input() -> io.writer {
+            ret io.new_writer(io.fd_buf_writer(in_fd, false));
+        }
+        fn output() -> io.reader {
+            ret io.FILE_reader(out_file, false);
+        }
+        impure fn close_input() {
+            os.libc.close(in_fd);
+        }
+        impure fn finish() -> int {
+            if (finished) {ret 0;}
+            finished = true;
+            os.libc.close(in_fd);
+            ret os.waitpid(pid);
+        }
+        drop {
+            if (!finished) {
+                os.libc.close(in_fd);
+                os.waitpid(pid);
+            }
+            os.libc.fclose(out_file);
+        }
+    }
+    ret @new_program(pid, pipe_input._1,
+                     os.fd_FILE(pipe_output._0),
+                     false);
+}
+
+impure fn program_output(str prog, vec[str] args)
+    -> rec(int status, str out) {
+    auto pr = start_program(prog, args);
+    pr.close_input();
+    auto out = pr.output();
+    auto buf = "";
+    while (!out.eof()) {
+        auto bytes = out.read_bytes(4096u);
+        buf += _str.unsafe_from_bytes(bytes);
+    }
+    ret rec(status=pr.finish(), out=buf);
+}
+
+
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End: