restructure dir, create makefile

1 files changed, 189 insertions, 0 deletions

diff --git a/src/exec.c b/src/exec.c
new file mode 100644
index 0000000..fccda7a
--- /dev/null
+++ b/src/exec.c
@@ -0,0 +1,189 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include "utils.h"
+#include "exec.h"
+#include "preproc.h"
+#include "expand.h"
+
+
+void execute_command(Command cmd, int* pgid) {
+
+    pid_t pid = fork();
+    
+    if (pid == 0) {
+      if (*pgid == -1) {
+            setpgid(0, 0);
+        } else {
+            setpgid(0, *pgid);
+        }
+        
+        dup2(cmd.stdin_fd, STDIN_FILENO);
+        dup2(cmd.stdout_fd, STDOUT_FILENO);
+
+        for (int j = 0; j < cmd.redirs.count; j++) {
+            FdRedirect fd_rd = *get_from_FdRedirectVec(&cmd.redirs, j);
+            dup2(fd_rd.new_fd, fd_rd.old_fd);
+        }
+
+        for (int i = 0; i < cmd.child_close_fds.count; i++) {
+            close(*get_from_IntVec(&cmd.child_close_fds, i));
+        }
+
+        signal(SIGINT,  SIG_DFL);
+        signal(SIGQUIT, SIG_DFL);
+        signal(SIGTSTP, SIG_DFL);
+        signal(SIGTTIN, SIG_DFL);
+        signal(SIGTTOU, SIG_DFL);
+
+        execvp(cmd.args[0], cmd.args);
+        exit(67);
+    }
+
+    if (*pgid == -1) {
+        setpgid(pid, pid);
+        *pgid = pid;
+    } else {
+        setpgid(pid, *pgid);
+    }
+}
+
+Command make_command(ExpandedPipelineElement elem) {
+    Command cmd = {
+        .child_close_fds = make_IntVec(64), 
+        .parent_close_fds = make_IntVec(64),
+        .redirs = make_FdRedirectVec(32),
+        .term = elem.conn,
+    };
+    StrVec arg_strs = make_StrVec(256);
+    for (int i = 0; i < elem.cmd_slots.count; i++) {
+        Slot curr_slot = *get_from_SlotVec(&elem.cmd_slots, i);
+        Slot next_slot;
+        int fd;
+        FdRedirect redir;
+        switch (curr_slot.kind) {
+            case SLOT_STR:
+                push_to_StrVec(&arg_strs, curr_slot.as.str);
+                break;
+            case SLOT_SPEC:
+                switch (curr_slot.as.spec) {
+                    case READ_REDIR:
+                        i++; 
+                        next_slot = *get_from_SlotVec(&elem.cmd_slots, i);
+                        if (next_slot.kind != SLOT_STR) exit(6);
+                        fd = open(next_slot.as.str, O_RDONLY, 0644);
+                        redir = (FdRedirect){.old_fd = STDIN_FILENO, .new_fd = fd};
+                        push_to_FdRedirectVec(&cmd.redirs, redir);
+                        push_to_IntVec(&cmd.parent_close_fds, fd);
+                        push_to_IntVec(&cmd.child_close_fds, fd);
+                        break;
+                    case WRITE_REDIR_TRUNC:
+                        i++; 
+                        next_slot = *get_from_SlotVec(&elem.cmd_slots, i);
+                        if (next_slot.kind != SLOT_STR) exit(6);
+                        fd = open(next_slot.as.str, O_WRONLY | O_CREAT | O_TRUNC , 0644);
+                        redir = (FdRedirect){.old_fd = STDOUT_FILENO, .new_fd = fd};
+                        push_to_FdRedirectVec(&cmd.redirs, redir);
+                        push_to_IntVec(&cmd.parent_close_fds, fd);
+                        push_to_IntVec(&cmd.child_close_fds, fd);
+                        break;
+                    case WRITE_REDIR_APPEND:
+                        i++; 
+                        next_slot = *get_from_SlotVec(&elem.cmd_slots, i);
+                        if (next_slot.kind != SLOT_STR) exit(6);
+                        fd = open(next_slot.as.str, O_WRONLY | O_CREAT | O_APPEND, 0644);
+                        redir = (FdRedirect){.old_fd = STDOUT_FILENO, .new_fd = fd};
+                        push_to_FdRedirectVec(&cmd.redirs, redir);
+                        push_to_IntVec(&cmd.parent_close_fds, fd);
+                        push_to_IntVec(&cmd.child_close_fds, fd);
+                        break;
+                    default:
+                        exit(7);
+                }
+                break;
+            default:
+                exit(67);
+            // TODO: other slot kinds
+        }
+    }
+    cmd.args = malloc(sizeof(char*) * arg_strs.count);
+    for (int j = 0; j < arg_strs.count; j++) {
+        cmd.args[j] = *get_from_StrVec(&arg_strs, j);
+    }
+    return cmd;
+}
+
+
+void run_cmds(CommandVec cmds) {
+    signal(SIGTTIN, SIG_IGN);
+    signal(SIGTTOU, SIG_IGN);
+
+    int trunk_fd = STDIN_FILENO;
+    int pgid = -1;
+
+    for (int i = 0; i < cmds.count; i++) {
+        Command cmd = *get_from_CommandVec(&cmds, i);
+        cmd.stdin_fd = trunk_fd;
+
+        if (i > 0) {
+            push_to_IntVec(&cmd.child_close_fds, trunk_fd);
+            push_to_IntVec(&cmd.parent_close_fds, trunk_fd); 
+        }
+
+        cmd.stdout_fd = STDOUT_FILENO;
+        if (cmd.term == CONN_PIPE) {
+            int pipe_fds[2];
+            pipe(pipe_fds);
+            cmd.stdout_fd = pipe_fds[1];
+            push_to_IntVec(&cmd.child_close_fds, pipe_fds[1]);
+            push_to_IntVec(&cmd.parent_close_fds, pipe_fds[1]);
+            trunk_fd = pipe_fds[0];
+        }
+
+        execute_command(cmd, &pgid);
+        
+        for (int j = 0; j < cmd.parent_close_fds.count; j++) {
+            close(*get_from_IntVec(&cmd.parent_close_fds, j));
+        }
+    }
+
+    tcsetpgrp(STDIN_FILENO, pgid); 
+    while (waitpid(-pgid, NULL, 0) > 0); 
+    tcsetpgrp(STDIN_FILENO, getpgrp());
+}
+
+
+CommandVec make_cmd_vec_pl(ExpandedPipeline pl) {
+    CommandVec cmds = make_CommandVec(256);
+    for (int i = 0; i < pl.count; i++) {
+        ExpandedPipelineElement elem = *get_from_ExpandedPipeline(&pl, i);
+        Command cmd = make_command(elem);
+        push_to_CommandVec(&cmds, cmd);
+    }
+    return cmds;
+}
+
+
+void process_input_line(char* line, ShellState* shstate) {
+    PreprocArena arena = {
+        .tokens = make_TokenVec(256),
+        .chunks = make_ChunkVec(256),
+        .regions = make_RegionVec(256),
+    };
+    TokenPtrVec line_tok_ptrs = lex(line, &arena);
+    Token* line_toks = malloc(sizeof(Token) * line_tok_ptrs.count);
+    for (int i = 0; i < line_tok_ptrs.count; i++) {
+        line_toks[i] = **get_from_TokenPtrVec(&line_tok_ptrs, i);
+    }
+    Pipeline pl = parse_tokstream(line_toks);
+    ExpandedPipeline exp_pl = expand_pipeline(&pl, shstate);
+    CommandVec cmds = make_cmd_vec_pl(exp_pl);
+    run_cmds(cmds); 
+    free(line_toks);
+}
+