Make sh able to execute from file

core/bin/hexd.c

@@ -1,4 +1,5 @@
 #include <sys/fcntl.h>
+#include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
@@ -47,11 +48,15 @@ int main(int argc, char **argv) {
     }
 
     path = argv[1];
-    printf("open file %s\n", path);
 
-    if ((fd = open(path, O_RDONLY, 0)) < 0) {
-        perror(path);
-        return -1;
+    if (!strcmp(path, "-")) {
+        fd = STDIN_FILENO;
+        printf("Reading from stdin\n");
+    } else {
+        if ((fd = open(path, O_RDONLY, 0)) < 0) {
+            perror(path);
+            return -1;
+        }
     }
 
     offset = 0;

etc/test.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo Something

sh/builtin.c

@@ -38,6 +38,42 @@ DEF_BUILTIN(clear) {
     return 0;
 }
 
+DEF_BUILTIN(echo) {
+    for (int i = 1; i < cmd->argc; ++i) {
+        printf("%s ", cmd->args[i]);
+    }
+    printf("\n");
+    return 0;
+}
+
+DEF_BUILTIN(into) {
+    if (cmd->argc < 3) {
+        printf("usage: into <filename> <command> ...\n");
+        return -1;
+    }
+
+    int pid = fork();
+    if (pid < 0) {
+        perror("fork()");
+        return -1;
+    }
+
+    if (pid == 0) {
+        close(STDIN_FILENO);
+        int fd = open(cmd->args[1], O_RDONLY, 0);
+        if (fd < 0) {
+            perror(cmd->args[1]);
+            return -1;
+        }
+
+        exit(execve(cmd->args[2], (const char *const *) &cmd->args[2], NULL));
+    } else {
+        int st;
+        waitpid(pid, &st);
+        return 0;
+    }
+}
+
 // TODO: support usernames (getpwnam_r)
 DEF_BUILTIN(setid) {
     if (cmd->argc == 2) {
@@ -78,8 +114,10 @@ static struct sh_builtin __builtins[] = {
     DECL_BUILTIN(builtins),
     DECL_BUILTIN(cd),
     DECL_BUILTIN(clear),
+    DECL_BUILTIN(echo),
     DECL_BUILTIN(exit),
     DECL_BUILTIN(setid),
+    DECL_BUILTIN(into),
     {NULL}
 };
 

sh/cmd.c

@@ -104,11 +104,16 @@ static int cmd_exec(const struct cmd_exec *cmd) {
 
 int eval(char *str) {
     struct cmd_exec cmd;
+    char *p;
 
     while (isspace(*str)) {
         ++str;
     }
 
+    if ((p = strchr(str, '#'))) {
+        *p = 0;
+    }
+
     if (!*str) {
         return 0;
     }

sh/sh.c

@@ -73,9 +73,38 @@ static void display_prompt(void) {
 }
 
 int main(int argc, char **argv) {
+    int fd = STDIN_FILENO;
     char linebuf[256];
     int res;
 
+    if (argc == 2) {
+        fd = open(argv[1], O_RDONLY, 0);
+
+        if (fd < 0) {
+            perror(argv[1]);
+            return -1;
+        }
+    } else if (argc != 1) {
+        printf("usage: sh [filename]\n");
+        return -1;
+    }
+
+    if (!isatty(fd)) {
+        while (1) {
+            if (gets_safe(fd, linebuf, sizeof(linebuf)) < 0) {
+                break;
+            }
+
+            eval(linebuf);
+        }
+
+        if (fd != STDIN_FILENO) {
+            close(fd);
+        }
+
+        return 0;
+    }
+
     while (1) {
         update_prompt();
         display_prompt();