Move some unfinished commands to the "pending" directory.

1 files changed, 392 insertions, 0 deletions

diff --git a/toys/pending/sh.c b/toys/pending/sh.c
new file mode 100644
index 00000000..2f09f63b
--- /dev/null
+++ b/toys/pending/sh.c
@@ -0,0 +1,392 @@
+/* sh.c - toybox shell
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ *
+ * The POSIX-2008/SUSv4 spec for this is at:
+ * http://opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
+ * and http://opengroup.org/onlinepubs/9699919799/utilities/sh.html
+ *
+ * The first link describes the following shell builtins:
+ *
+ *   break colon continue dot eval exec exit export readonly return set shift
+ *   times trap unset
+ *
+ * The second link (the utilities directory) also contains specs for the
+ * following shell builtins:
+ *
+ *   alias bg cd command fc fg getopts hash jobs kill read type ulimit
+ *   umask unalias wait
+ *
+ * Things like the bash man page are good to read too.
+ *
+ * TODO: // Handle embedded NUL bytes in the command line.
+
+USE_SH(NEWTOY(cd, NULL, TOYFLAG_NOFORK))
+USE_SH(NEWTOY(exit, NULL, TOYFLAG_NOFORK))
+
+USE_SH(NEWTOY(sh, "c:i", TOYFLAG_BIN))
+USE_SH(OLDTOY(toysh, sh, "c:i", TOYFLAG_BIN))
+
+config SH
+  bool "sh (toysh)"
+  default n
+  help
+    usage: sh [-c command] [script]
+
+    Command shell.  Runs a shell script, or reads input interactively
+    and responds to it.
+
+    -c	command line to execute
+
+config SH_TTY
+  bool "Interactive shell (terminal control)"
+  default n
+  depends on SH
+  help
+    Add terminal control to toysh.  This is necessary for interactive use,
+    so the shell isn't killed by CTRL-C.
+
+config SH_PROFILE
+  bool "Profile support"
+  default n
+  depends on SH_TTY
+  help
+    Read /etc/profile and ~/.profile when running interactively.
+
+    Also enables the built-in command "source".
+
+config SH_JOBCTL
+  bool "Job Control (fg, bg, jobs)"
+  default n
+  depends on SH_TTY
+  help
+    Add job control to toysh.  This lets toysh handle CTRL-Z, and enables
+    the built-in commands "fg", "bg", and "jobs".
+
+    With pipe support, enable use of "&" to run background processes.
+
+config SH_FLOWCTL
+  bool "Flow control (if, while, for, functions)"
+  default n
+  depends on SH
+  help
+    Add flow control to toysh.  This enables the if/then/else/fi,
+    while/do/done, and for/do/done constructs.
+
+    With pipe support, this enables the ability to define functions
+    using the "function name" or "name()" syntax, plus curly brackets
+    "{ }" to group commands.
+
+config SH_QUOTES
+  bool "Smarter argument parsing (quotes)"
+  default n
+  depends on SH
+  help
+    Add support for parsing "" and '' style quotes to the toysh command
+    parser, with lets arguments have spaces in them.
+
+config SH_WILDCARDS
+  bool "Wildcards ( ?*{,} )"
+  default n
+  depends on SH_QUOTES
+  help
+    Expand wildcards in argument names, ala "ls -l *.t?z" and
+    "rm subdir/{one,two,three}.txt".
+
+config SH_PROCARGS
+  bool "Executable arguments ( `` and $() )"
+  default n
+  depends on SH_QUOTES
+  help
+    Add support for executing arguments contianing $() and ``, using
+    the output of the command as the new argument value(s).
+
+    (Bash calls this "command substitution".)
+
+config SH_ENVVARS
+  bool "Environment variable support"
+  default n
+  depends on SH_QUOTES
+  help
+    Substitute environment variable values for $VARNAME or ${VARNAME},
+    and enable the built-in command "export".
+
+config SH_LOCALS
+  bool "Local variables"
+  default n
+  depends on SH_ENVVARS
+  help
+    Support for local variables, fancy prompts ($PS1), the "set" command,
+    and $?.
+
+config SH_ARRAYS
+  bool "Array variables"
+  default n
+  depends on SH_LOCALS
+  help
+    Support for ${blah[blah]} style array variables.
+
+config SH_PIPES
+  bool "Pipes and redirects ( | > >> < << & && | || () ; )"
+  default n
+  depends on SH
+  help
+    Support multiple commands on the same command line.  This includes
+    | pipes, > >> < redirects, << here documents, || && conditional
+    execution, () subshells, ; sequential execution, and (with job
+    control) & background processes.
+
+config SH_BUILTINS
+  bool "Builtin commands"
+  default n
+  depends on SH
+  help
+    Adds the commands exec, fg, bg, help, jobs, pwd, export, source, set,
+    unset, read, alias.
+
+config EXIT
+  bool
+  default n
+  depends on SH
+  help
+    usage: exit [status]
+
+    Exit shell.  If no return value supplied on command line, use value
+    of most recent command, or 0 if none.
+
+config CD
+  bool
+  default n
+  depends on SH
+  help
+    usage: cd [path]
+
+    Change current directory.  With no arguments, go to $HOME.
+
+config CD_P
+  bool # "-P support for cd"
+  default n
+  depends on SH
+  help
+    usage: cd [-PL]
+
+    -P    Physical path: resolve symlinks in path.
+    -L    Cancel previous -P and restore default behavior.
+*/
+
+#define FOR_sh
+#include "toys.h"
+
+GLOBALS(
+  char *command;
+)
+
+// A single executable, its arguments, and other information we know about it.
+#define SH_FLAG_EXIT    1
+#define SH_FLAG_SUSPEND 2
+#define SH_FLAG_PIPE    4
+#define SH_FLAG_AND     8
+#define SH_FLAG_OR      16
+#define SH_FLAG_AMP     32
+#define SH_FLAG_SEMI    64
+#define SH_FLAG_PAREN   128
+
+// What we know about a single process.
+struct command {
+  struct command *next;
+  int flags;              // exit, suspend, && ||
+  int pid;                // pid (or exit code)
+  int argc;
+  char *argv[0];
+};
+
+// A collection of processes piped into/waiting on each other.
+struct pipeline {
+  struct pipeline *next;
+  int job_id;
+  struct command *cmd;
+  char *cmdline;         // Unparsed line for display purposes
+  int cmdlinelen;        // How long is cmdline?
+};
+
+// Parse one word from the command line, appending one or more argv[] entries
+// to struct command.  Handles environment variable substitution and
+// substrings.  Returns pointer to next used byte, or NULL if it
+// hit an ending token.
+static char *parse_word(char *start, struct command **cmd)
+{
+  char *end;
+
+  // Detect end of line (and truncate line at comment)
+  if (CFG_SH_PIPES && strchr("><&|(;", *start)) return 0;
+
+  // Grab next word.  (Add dequote and envvar logic here)
+  end = start;
+  while (*end && !isspace(*end)) end++;
+  (*cmd)->argv[(*cmd)->argc++] = xstrndup(start, end-start);
+
+  // Allocate more space if there's no room for NULL terminator.
+
+  if (!((*cmd)->argc & 7))
+    *cmd=xrealloc(*cmd,
+        sizeof(struct command) + ((*cmd)->argc+8)*sizeof(char *));
+  (*cmd)->argv[(*cmd)->argc] = 0;
+  return end;
+}
+
+// Parse a line of text into a pipeline.
+// Returns a pointer to the next line.
+
+static char *parse_pipeline(char *cmdline, struct pipeline *line)
+{
+  struct command **cmd = &(line->cmd);
+  char *start = line->cmdline = cmdline;
+
+  if (!cmdline) return 0;
+
+  if (CFG_SH_JOBCTL) line->cmdline = cmdline;
+
+  // Parse command into argv[]
+  for (;;) {
+    char *end;
+
+    // Skip leading whitespace and detect end of line.
+    while (isspace(*start)) start++;
+    if (!*start || *start=='#') {
+      if (CFG_SH_JOBCTL) line->cmdlinelen = start-cmdline;
+      return 0;
+    }
+
+    // Allocate next command structure if necessary
+    if (!*cmd) *cmd = xzalloc(sizeof(struct command)+8*sizeof(char *));
+
+    // Parse next argument and add the results to argv[]
+    end = parse_word(start, cmd);
+
+    // If we hit the end of this command, how did it end?
+    if (!end) {
+      if (CFG_SH_PIPES && *start) {
+        if (*start==';') {
+          start++;
+          break;
+        }
+        // handle | & < > >> << || &&
+      }
+      break;
+    }
+    start = end;
+  }
+
+  if (CFG_SH_JOBCTL) line->cmdlinelen = start-cmdline;
+
+  return start;
+}
+
+// Execute the commands in a pipeline
+static void run_pipeline(struct pipeline *line)
+{
+  struct toy_list *tl;
+  struct command *cmd = line->cmd;
+  if (!cmd || !cmd->argc) return;
+
+  tl = toy_find(cmd->argv[0]);
+  // Is this command a builtin that should run in this process?
+  if (tl && (tl->flags & TOYFLAG_NOFORK)) {
+    struct toy_context temp;
+    jmp_buf rebound;
+
+    // This fakes lots of what toybox_main() does.
+    memcpy(&temp, &toys, sizeof(struct toy_context));
+    memset(&toys, 0, sizeof(struct toy_context));
+
+    if (!setjmp(rebound)) {
+      toys.rebound = rebound;
+      toy_init(tl, cmd->argv);
+      tl->toy_main();
+    }
+    cmd->pid = toys.exitval;
+    if (toys.optargs != toys.argv+1) free(toys.optargs);
+    if (toys.old_umask) umask(toys.old_umask);
+    memcpy(&toys, &temp, sizeof(struct toy_context));
+  } else {
+    int status;
+
+    cmd->pid = vfork();
+    if (!cmd->pid) xexec(cmd->argv);
+    else waitpid(cmd->pid, &status, 0);
+
+    if (CFG_SH_FLOWCTL || CFG_SH_PIPES) {
+      if (WIFEXITED(status)) cmd->pid = WEXITSTATUS(status);
+      if (WIFSIGNALED(status)) cmd->pid = WTERMSIG(status);
+    }
+  }
+
+  return;
+}
+
+// Free the contents of a command structure
+static void free_cmd(void *data)
+{
+  struct command *cmd=(struct command *)data;
+
+  while(cmd->argc) free(cmd->argv[--cmd->argc]);
+}
+
+
+// Parse a command line and do what it says to do.
+static void handle(char *command)
+{
+  struct pipeline line;
+  char *start = command;
+
+  // Loop through commands in this line
+
+  for (;;) {
+
+    // Parse a group of connected commands
+
+    memset(&line,0,sizeof(struct pipeline));
+    start = parse_pipeline(start, &line);
+    if (!line.cmd) break;
+
+    // Run those commands
+
+    run_pipeline(&line);
+    llist_traverse(line.cmd, free_cmd);
+  }
+}
+
+void cd_main(void)
+{
+  char *dest = *toys.optargs ? *toys.optargs : getenv("HOME");
+  xchdir(dest);
+}
+
+void exit_main(void)
+{
+  exit(*toys.optargs ? atoi(*toys.optargs) : 0);
+}
+
+void sh_main(void)
+{
+  FILE *f;
+
+  // Set up signal handlers and grab control of this tty.
+  if (CFG_SH_TTY) {
+    if (isatty(0)) toys.optflags |= 1;
+  }
+  f = *toys.optargs ? xfopen(*toys.optargs, "r") : NULL;
+  if (TT.command) handle(TT.command);
+  else {
+    size_t cmdlen = 0;
+    for (;;) {
+      char *command = 0;
+      if (!f) xputc('$');
+      if (1 > getline(&command, &cmdlen, f ? f : stdin)) break;
+      handle(command);
+      free(command);
+    }
+  }
+
+  toys.exitval = 1;
+}