1 files changed, 33 insertions, 3 deletions

diff --git a/src/preproc.c b/src/preproc.c
index 8865968..9c26c5f 100644
--- a/src/preproc.c
+++ b/src/preproc.c
@@ -1,7 +1,11 @@
 #include <assert.h>
 #include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+
 #include "syntax.h"
 #include "utils.h"
+#include "stages.h"
 
 
 typedef struct {
@@ -35,6 +39,28 @@ void split_str_on_space(char* str, StrVec* result) {
 }
 
 
+char* get_cmdsub_output(TokenVec sub_region, ShellState* shstate) {
+    int pipe_fds[2];
+    pipe(pipe_fds);
+    
+    PipelineTree sub_tree = process_ast(sub_region, shstate);
+    // TODO: tree cleanup
+
+    execute_pipeline_tree(*sub_tree.root, shstate, STDIN_FILENO, pipe_fds[1]);
+
+    String output_buf = make_String(256);
+
+    char str_buf[256];
+    ssize_t len;
+    while ((len = read(pipe_fds[0], str_buf, sizeof(str_buf))) > 0) {
+        append_str_to_String(&output_buf, str_buf);
+    }
+    close(pipe_fds[0]);
+    close(pipe_fds[1]);
+    return inner(&output_buf);
+}
+
+
 void process_chunk(Chunk chunk, SplitBuilder* builder, ShellState* shstate) {
     assert(!(chunk.qmode == SINGLE_Q && chunk.kind != CHUNK_LIT));
 
@@ -46,6 +72,9 @@ void process_chunk(Chunk chunk, SplitBuilder* builder, ShellState* shstate) {
         case CHUNK_VAR:
             chunk_str = get_var(chunk.as.varname, shstate);
             break;
+        case CHUNK_CMDSUB:
+            chunk_str = get_cmdsub_output(*(TokenVec*)chunk.as.cmdsub_toks, shstate);
+            break;
         default:
             exit(77);
     }
@@ -146,7 +175,7 @@ Pipeline* process_token_sequence(TokenVec tokens, PipelineVec* pl_pool, ShellSta
                             case OP_REDIR_W_TRUNC:
                                 next_tok = *get_from_ExpandedTokenVec(&exp_tokens, ++i);                               
                                 assert(next_tok.kind == TOK_WORD);
-                                rd = (Redirect){.kind = REDIR_WRITE_TRUNC, .as.filename = next_tok.as.word};
+     rd = (Redirect){.kind = REDIR_WRITE_TRUNC, .as.filename = next_tok.as.word};
                                 push_to_RedirectVec(&curr_cmd.redirects, rd);
                                 break;
                             default:
@@ -168,8 +197,9 @@ Pipeline* process_token_sequence(TokenVec tokens, PipelineVec* pl_pool, ShellSta
 }
 
 
-PipelineTree process_ast(Ast ast, ShellState* shstate) {
+PipelineTree process_ast(TokenVec root, ShellState* shstate) {
     PipelineVec pls = make_PipelineVec(256);
-    Pipeline* root_pl = process_token_sequence(*ast.root, &pls, shstate);
+    Pipeline* root_pl = process_token_sequence(root, &pls, shstate);
     return (PipelineTree){.pl_pool = pls, root_pl};
+    // TODO: ast cleanup
 }