start work on cmdsub

6 files changed, 70 insertions, 21 deletions

diff --git a/src/exec.c b/src/exec.c
index 86175a9..fb579ad 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -36,7 +36,7 @@ void source_script(char* fname, ShellState* shstate) {
 
     while (getline(&line, &len, fp) != -1) {
 		line[strcspn(line, "\r\n")] = '\0';
-        execute_line(line, shstate);
+        execute_string_line(line, shstate);
     }
     free(line);
     fclose(fp);
@@ -265,9 +265,9 @@ void execute_command_pipeline(Pipeline pipeline, int stdin_fd, int stdout_fd, bo
     }
 }
 
-void execute_pipeline_tree(PipelineTree pltree, ShellState* shstate) {
+void execute_pipeline_tree(Pipeline root_pl, ShellState* shstate, int stdin_fd, int stdout_fd) {
     int pgid = -1;
     signal(SIGTTIN, SIG_IGN);
     signal(SIGTTOU, SIG_IGN);
-    execute_command_pipeline(*pltree.root, STDIN_FILENO, STDOUT_FILENO, true, &pgid, shstate); 
+    execute_command_pipeline(root_pl, stdin_fd, stdout_fd, true, &pgid, shstate); 
 }
diff --git a/src/lexparse.c b/src/lexparse.c
index eae5c16..2fcd909 100644
--- a/src/lexparse.c
+++ b/src/lexparse.c
@@ -16,6 +16,9 @@ typedef struct {
 
 DECLARE_MAYBE(Token, MaybeToken)
 
+TokenVec* lex_level(char* line, size_t* pos, char until, TokenVecVec* tok_seq_pool);
+
+
 MaybeToken consolidate_buffer(LexingBuffer* buf) {
     if (buf->lit_germ.count > 0) {
         push_to_Word(&buf->word_germ, (Chunk){
@@ -40,11 +43,26 @@ MaybeToken consolidate_buffer(LexingBuffer* buf) {
 }
 
 
-static MaybeChunk handle_dollar_expansion(char* line, size_t* pos, QuotationMode qmode) {
+static MaybeChunk handle_dollar_expansion(char* line, size_t* pos, QuotationMode qmode, TokenVecVec* tok_seq_pool) {
     (*pos)++;
     if (line[*pos] == '(') {
-        // TODO
-        exit(66);
+        (*pos)++;
+        if (line[*pos] == '(') {
+            // TODO: arithm parsing
+            exit(66);
+        } else {
+            TokenVec* sub_region = lex_level(line, pos, ')', tok_seq_pool);
+            (*pos)++;      // consume paren
+            return (MaybeChunk){
+                .some = true,
+                .value = (Chunk){
+                    .qmode = qmode,
+                    .kind = CHUNK_CMDSUB,
+                    .as.cmdsub_toks = sub_region,
+                }
+            };
+        }
+
     } else if (line[*pos] == '_' || isalnum(line[*pos])){
         String buf = make_String(256); 
         while (line[*pos] == '_' || isalnum(line[*pos])) {
@@ -96,7 +114,7 @@ static Chunk collect_single_q_section(char* line, size_t* pos) {
     };
 }
 
-static void collect_double_q_section(char* line, Word* result_buf, size_t* pos) {
+static void collect_double_q_section(char* line, Word* result_buf, size_t* pos, TokenVecVec* tok_seq_pool) {
     // TODO: add the extra double-q expansions
     (*pos)++;
     String lit_buf = make_String(256);
@@ -104,7 +122,7 @@ static void collect_double_q_section(char* line, Word* result_buf, size_t* pos)
     while (line[*pos] != '\"' && line[*pos] != '\0') {
         // TODO: handle escapes
         if (line[*pos] == '$') {
-            MaybeChunk m_dollar = handle_dollar_expansion(line, pos, DOUBLE_Q);
+            MaybeChunk m_dollar = handle_dollar_expansion(line, pos, DOUBLE_Q, tok_seq_pool);
             if (m_dollar.some) {
                 if (lit_buf.count>0) {
                     push_to_Word(result_buf, (Chunk){.qmode = DOUBLE_Q, .kind = CHUNK_LIT, .as.lit_str = inner(&lit_buf)});
@@ -211,9 +229,9 @@ TokenVec* lex_level(char* line, size_t* pos, char until, TokenVecVec* tok_seq_po
             Chunk chunk = collect_single_q_section(line, pos);
             push_to_Word(&buf.word_germ, chunk);
         } else if (line[*pos] == '\"') {
-            collect_double_q_section(line, &buf.word_germ,pos);
+            collect_double_q_section(line, &buf.word_germ,pos, tok_seq_pool);
         } else if (line[*pos] == '$') {
-            MaybeChunk dollar_chunk = handle_dollar_expansion(line, pos, UN_Q);
+            MaybeChunk dollar_chunk = handle_dollar_expansion(line, pos, UN_Q, tok_seq_pool);
             if (dollar_chunk.some) {
                 push_to_Word(&buf.word_germ, dollar_chunk.value); 
             } else {
diff --git a/src/main.c b/src/main.c
index 9e30c27..f93d32a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include <unistd.h>
 #include <stdio.h>
 #include <readline/readline.h>
 #include <readline/history.h>
@@ -10,10 +11,10 @@
 #include "utils.h"
 
 
-void execute_line(char *line, ShellState *shstate) {
+void execute_string_line(char *line, ShellState *shstate) {
     Ast ast = lex(line);
-    PipelineTree pltree = process_ast(ast, shstate);
-    execute_pipeline_tree(pltree, shstate);
+    PipelineTree pltree = process_ast(*ast.root, shstate);
+    execute_pipeline_tree(*pltree.root, shstate, STDIN_FILENO, STDOUT_FILENO);
 }
 
 
@@ -25,7 +26,7 @@ int main() {
         line = readline("$ ");
         if (line[0] == '\0') continue;  
         add_history(line);
-        execute_line(line, &shstate);
+        execute_string_line(line, &shstate);
     }
     free(line);
 }
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
 }
diff --git a/src/stages.h b/src/stages.h
index e731533..6bcdd51 100644
--- a/src/stages.h
+++ b/src/stages.h
@@ -4,7 +4,7 @@
 #include "utils.h"
 
 Ast lex(char* input);
-PipelineTree process_ast(Ast ast, ShellState* shstate);
-void execute_pipeline_tree(PipelineTree pltree, ShellState* shstate);
+PipelineTree process_ast(TokenVec root, ShellState* shstate);
+void execute_pipeline_tree(Pipeline root_pl, ShellState* shstate, int stdin_fd, int stdout_fd);
 void source_script(char* fname, ShellState* shstate);
-void execute_line(char* line, ShellState* shstate);
+void execute_string_line(char* line, ShellState* shstate);
diff --git a/src/syntax.h b/src/syntax.h
index 9b34818..80ab067 100644
--- a/src/syntax.h
+++ b/src/syntax.h
@@ -61,7 +61,7 @@ typedef struct {
         char* lit_str;
         char* varname;
         ArithmAst arithm_expr;
-        // TODO: CHUNK_CMDSUB
+        void* cmdsub_toks;      // NOTE: TokenVec
     } as;
 } Chunk;