* Brace Expansion
* Tilde Expansion
* fancy forms of Parameter Expansion
+ * aliases
* Arithmetic Expansion
* <(list) and >(list) Process Substitution
* reserved words: case, esac, select, function
* test magic exec
* handle children going into background
* clean up recognition of null pipes
- * have builtin_exec set flag to avoid restore_redirects
* check setting of global_argc and global_argv
* control-C handling, probably with longjmp
- * VAR=value prefix for simple commands
* follow IFS rules more precisely, including update semantics
* figure out what to do with backslash-newline
* explain why we use signal instead of sigaction
* continuation lines, both explicit and implicit - done?
* memory leak finding and plugging - done?
* more testing, especially quoting rules and redirection
+ * document how quoting rules not precisely followed for variable assignments
* maybe change map[] to use 2-bit entries
* (eventually) remove all the printf's
*
#define applet_name "hush"
#include "standalone.h"
#define shell_main main
-#define BB_FEATURE_SH_SIMPLE_PROMPT
+#undef BB_FEATURE_SH_FANCY_PROMPT
#endif
typedef enum {
reserved_style r_mode; /* supports if, for, while, until */
};
-struct jobset {
- struct pipe *head; /* head of list of running jobs */
- struct pipe *fg; /* current foreground job */
-};
-
struct close_me {
int fd;
struct close_me *next;
};
+struct variables {
+ char *name;
+ char *value;
+ int flg_export;
+ int flg_read_only;
+ struct variables *next;
+};
+
/* globals, connect us to the outside world
* the first three support $?, $#, and $1 */
char **global_argv;
unsigned int last_return_code;
extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
-/* Variables we export */
-unsigned int shell_context; /* Used in cmdedit.c to reset the
- * context when someone hits ^C */
-
/* "globals" within this file */
-static char *ifs=NULL;
+static char *ifs;
static char map[256];
-static int fake_mode=0;
-static int interactive=0;
-static struct close_me *close_me_head = NULL;
+static int fake_mode;
+static int interactive;
+static struct close_me *close_me_head;
static const char *cwd;
-static struct jobset *job_list;
-static unsigned int last_bg_pid=0;
+static struct pipe *job_list;
+static unsigned int last_bg_pid;
+static unsigned int last_jobid;
+static unsigned int shell_terminal;
static char *PS1;
-static char *PS2 = "> ";
+static char *PS2;
+struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
+struct variables *top_vars = &shell_ver;
+
#define B_CHUNK (100)
#define B_NOSPAC 1
-#define MAX_LINE 256 /* for cwd */
-#define MAX_READ 256 /* for builtin_read */
typedef struct {
char *data;
* available? Where is it documented? */
struct in_str {
const char *p;
+ char peek_buf[2];
int __promptme;
int promptmode;
FILE *file;
va_end(args);
}
#else
-static void debug_printf(const char *format, ...) { }
+static inline void debug_printf(const char *format, ...) { }
#endif
#define final_printf debug_printf
-void __syntax(char *file, int line) {
- fprintf(stderr,"syntax error %s:%d\n",file,line);
+static void __syntax(char *file, int line) {
+ error_msg("syntax error %s:%d", file, line);
}
#define syntax() __syntax(__FILE__, __LINE__)
static int builtin_jobs(struct child_prog *child);
static int builtin_pwd(struct child_prog *child);
static int builtin_read(struct child_prog *child);
+static int builtin_set(struct child_prog *child);
static int builtin_shift(struct child_prog *child);
static int builtin_source(struct child_prog *child);
static int builtin_umask(struct child_prog *child);
static void close_all();
/* "run" the final data structures: */
static char *indenter(int i);
-static int run_list_test(struct pipe *head, int indent);
-static int run_pipe_test(struct pipe *pi, int indent);
+static int free_pipe_list(struct pipe *head, int indent);
+static int free_pipe(struct pipe *pi, int indent);
/* really run the final data structures: */
static int setup_redirects(struct child_prog *prog, int squirrel[]);
-static int pipe_wait(struct pipe *pi);
static int run_list_real(struct pipe *pi);
static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
static int run_pipe_real(struct pipe *pi);
static int globhack(const char *src, int flags, glob_t *pglob);
static int glob_needed(const char *s);
static int xglob(o_string *dest, int flags, glob_t *pglob);
+/* variable assignment: */
+static int is_assignment(const char *s);
/* data structure manipulation: */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
static void initialize_context(struct p_context *ctx);
static int parse_string_outer(const char *s);
static int parse_file_outer(FILE *f);
/* job management: */
-static void checkjobs();
+static int checkjobs(struct pipe* fg_pipe);
static void insert_bg_job(struct pipe *pi);
static void remove_bg_job(struct pipe *pi);
-static void free_pipe(struct pipe *pi);
+/* local variable support */
+static char *get_local_var(const char *var);
+static void unset_local_var(const char *name);
+static int set_local_var(const char *s, int flg_export);
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
{"continue", "Continue for, while or until loop", builtin_not_written},
{"env", "Print all environment variables", builtin_env},
{"eval", "Construct and run shell command", builtin_not_written},
- {"exec", "Exec command, replacing this shell with the exec'd process", builtin_exec},
+ {"exec", "Exec command, replacing this shell with the exec'd process",
+ builtin_exec},
{"exit", "Exit from shell()", builtin_exit},
{"export", "Set environment variable", builtin_export},
{"fg", "Bring job into the foreground", builtin_fg_bg},
{"pwd", "Print current directory", builtin_pwd},
{"read", "Input environment variable", builtin_read},
{"return", "Return from a function", builtin_not_written},
- {"set", "Set/unset shell options", builtin_not_written},
+ {"set", "Set/unset shell local variables", builtin_set},
{"shift", "Shift positional parameters", builtin_shift},
{"trap", "Trap signals", builtin_not_written},
{"ulimit","Controls resource limits", builtin_not_written},
{NULL, NULL, NULL}
};
+static const char *set_cwd(void)
+{
+ if(cwd==unknown)
+ cwd = NULL; /* xgetcwd(arg) called free(arg) */
+ cwd = xgetcwd((char *)cwd);
+ if (!cwd)
+ cwd = unknown;
+ return cwd;
+}
+
+
/* built-in 'cd <path>' handler */
static int builtin_cd(struct child_prog *child)
{
printf("cd: %s: %s\n", newdir, strerror(errno));
return EXIT_FAILURE;
}
- cwd = xgetcwd((char *)cwd);
- if (!cwd)
- cwd = unknown;
+ set_cwd();
return EXIT_SUCCESS;
}
/* built-in 'export VAR=value' handler */
static int builtin_export(struct child_prog *child)
{
- int res;
+ int res = 0;
+ char *name = child->argv[1];
- if (child->argv[1] == NULL) {
+ if (name == NULL) {
return (builtin_env(child));
}
- /* FIXME -- I leak memory. This will be
- * fixed up properly when we add local
- * variable support -- I hope */
- res = putenv(strdup(child->argv[1]));
- if (res)
- fprintf(stderr, "export: %s\n", strerror(errno));
- return (res);
+
+ name = strdup(name);
+
+ if(name) {
+ char *value = strchr(name, '=');
+
+ if (!value) {
+ char *tmp;
+ /* They are exporting something without an =VALUE */
+
+ value = get_local_var(name);
+ if (value) {
+ size_t ln = strlen(name);
+
+ tmp = realloc(name, ln+strlen(value)+2);
+ if(tmp==NULL)
+ res = -1;
+ else {
+ sprintf(tmp+ln, "=%s", value);
+ name = tmp;
+ }
+ } else {
+ /* bash does not return an error when trying to export
+ * an undefined variable. Do likewise. */
+ res = 1;
+ }
+ }
+ }
+ if (res<0)
+ perror_msg("export");
+ else if(res==0)
+ res = set_local_var(name, 1);
+ else
+ res = 0;
+ free(name);
+ return res;
}
/* built-in 'fg' and 'bg' handler */
int i, jobnum;
struct pipe *pi=NULL;
+ if (!interactive)
+ return EXIT_FAILURE;
/* If they gave us no args, assume they want the last backgrounded task */
if (!child->argv[1]) {
- for (pi = job_list->head; pi; pi = pi->next) {
- if (pi->progs && pi->progs->pid == last_bg_pid) {
+ for (pi = job_list; pi; pi = pi->next) {
+ if (pi->jobid == last_jobid) {
break;
}
}
error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
return EXIT_FAILURE;
}
-
- for (pi = job_list->head; pi; pi = pi->next) {
+ for (pi = job_list; pi; pi = pi->next) {
if (pi->jobid == jobnum) {
break;
}
return EXIT_FAILURE;
}
}
+
if (*child->argv[0] == 'f') {
- /* Make this job the foreground job */
- signal(SIGTTOU, SIG_IGN);
- /* suppress messages when run from /linuxrc mag@sysgo.de */
- if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
- perror_msg("tcsetpgrp");
- signal(SIGTTOU, SIG_DFL);
- job_list->fg = pi;
+ /* Put the job into the foreground. */
+ tcsetpgrp(shell_terminal, pi->pgrp);
}
/* Restart the processes in the job */
for (i = 0; i < pi->num_progs; i++)
pi->progs[i].is_stopped = 0;
- kill(-pi->pgrp, SIGCONT);
+ if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
+ if (i == ESRCH) {
+ remove_bg_job(pi);
+ } else {
+ perror_msg("kill (SIGCONT)");
+ }
+ }
pi->stopped_progs = 0;
return EXIT_SUCCESS;
struct pipe *job;
char *status_string;
- for (job = job_list->head; job; job = job->next) {
+ for (job = job_list; job; job = job->next) {
if (job->running_progs == job->stopped_progs)
status_string = "Stopped";
else
status_string = "Running";
+
printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
}
return EXIT_SUCCESS;
/* built-in 'pwd' handler */
static int builtin_pwd(struct child_prog *dummy)
{
- cwd = xgetcwd((char *)cwd);
- if (!cwd)
- cwd = unknown;
- puts(cwd);
+ puts(set_cwd());
return EXIT_SUCCESS;
}
/* built-in 'read VAR' handler */
static int builtin_read(struct child_prog *child)
{
- int res = 0, len, newlen;
- char *s;
- char string[MAX_READ];
+ int res;
if (child->argv[1]) {
- /* argument (VAR) given: put "VAR=" into buffer */
- strcpy(string, child->argv[1]);
- len = strlen(string);
- string[len++] = '=';
- string[len] = '\0';
- /* XXX would it be better to go through in_str? */
- fgets(&string[len], sizeof(string) - len, stdin); /* read string */
- newlen = strlen(string);
- if(newlen > len)
- string[--newlen] = '\0'; /* chomp trailing newline */
- /*
- ** string should now contain "VAR=<value>"
- ** copy it (putenv() won't do that, so we must make sure
- ** the string resides in a static buffer!)
- */
- res = -1;
- if((s = strdup(string)))
- res = putenv(s);
+ char string[BUFSIZ];
+ char *var = 0;
+
+ string[0] = 0; /* In case stdin has only EOF */
+ /* read string */
+ fgets(string, sizeof(string), stdin);
+ chomp(string);
+ var = malloc(strlen(child->argv[1])+strlen(string)+2);
+ if(var) {
+ sprintf(var, "%s=%s", child->argv[1], string);
+ res = set_local_var(var, 0);
+ } else
+ res = -1;
if (res)
- fprintf(stderr, "read: %s\n", strerror(errno));
+ fprintf(stderr, "read: %m\n");
+ free(var); /* So not move up to avoid breaking errno */
+ return res;
+ } else {
+ do res=getchar(); while(res!='\n' && res!=EOF);
+ return 0;
}
+}
+
+/* built-in 'set VAR=value' handler */
+static int builtin_set(struct child_prog *child)
+{
+ char *temp = child->argv[1];
+ struct variables *e;
+
+ if (temp == NULL)
+ for(e = top_vars; e; e=e->next)
+ printf("%s=%s\n", e->name, e->value);
else
- fgets(string, sizeof(string), stdin);
+ set_local_var(temp, 0);
- return (res);
+ return EXIT_SUCCESS;
}
+
/* Built-in 'shift' handler */
static int builtin_shift(struct child_prog *child)
{
/* XXX search through $PATH is missing */
input = fopen(child->argv[1], "r");
if (!input) {
- fprintf(stderr, "Couldn't open file '%s'\n", child->argv[1]);
+ error_msg("Couldn't open file '%s'", child->argv[1]);
return EXIT_FAILURE;
}
/* built-in 'unset VAR' handler */
static int builtin_unset(struct child_prog *child)
{
- if (child->argv[1] == NULL) {
- fprintf(stderr, "unset: parameter required.\n");
- return EXIT_FAILURE;
- }
- unsetenv(child->argv[1]);
+ /* bash returned already true */
+ unset_local_var(child->argv[1]);
return EXIT_SUCCESS;
}
static inline void cmdedit_set_initial_prompt(void)
{
-#ifdef BB_FEATURE_SH_SIMPLE_PROMPT
+#ifndef BB_FEATURE_SH_FANCY_PROMPT
PS1 = NULL;
#else
PS1 = getenv("PS1");
static inline void setup_prompt_string(int promptmode, char **prompt_str)
{
debug_printf("setup_prompt_string %d ",promptmode);
-#ifdef BB_FEATURE_SH_SIMPLE_PROMPT
+#ifndef BB_FEATURE_SH_FANCY_PROMPT
/* Set up the prompt */
if (promptmode == 1) {
if (PS1)
*prompt_str = PS2;
}
#else
- *prompt_str = (promptmode==0)? PS1 : PS2;
+ *prompt_str = (promptmode==1)? PS1 : PS2;
#endif
debug_printf("result %s\n",*prompt_str);
}
** child processes (rob@sysgo.de)
*/
cmdedit_read_input(prompt_str, the_command);
- cmdedit_terminate();
#else
fputs(prompt_str, stdout);
fflush(stdout);
the_command[0]=fgetc(i->file);
the_command[1]='\0';
#endif
+ fflush(stdout);
i->p = the_command;
}
/* need to double check i->file because we might be doing something
* more complicated by now, like sourcing or substituting. */
if (i->__promptme && interactive && i->file == stdin) {
- get_user_input(i);
+ while(! i->p || (interactive && strlen(i->p)==0) ) {
+ get_user_input(i);
+ }
i->promptmode=2;
i->__promptme = 0;
if (i->p && *i->p) {
if (i->p && *i->p) {
return *i->p;
} else {
- static char buffer[2];
- buffer[0] = fgetc(i->file);
- buffer[1] = '\0';
- i->p = buffer;
+ i->peek_buf[0] = fgetc(i->file);
+ i->peek_buf[1] = '\0';
+ i->p = i->peek_buf;
debug_printf("b_peek: got a %d\n", *i->p);
- return *i->p;
+ return *i->p;
}
}
struct redir_struct *redir;
for (redir=prog->redirects; redir; redir=redir->next) {
+ if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
+ /* something went wrong in the parse. Pretend it didn't happen */
+ continue;
+ }
if (redir->dup == -1) {
mode=redir_table[redir->type].mode;
openfd = open(redir->word.gl_pathv[0], mode, 0666);
if (openfd < 0) {
/* this could get lost if stderr has been redirected, but
bash and ash both lose it as well (though zsh doesn't!) */
- fprintf(stderr,"error opening %s: %s\n", redir->word.gl_pathv[0],
- strerror(errno));
+ perror_msg("error opening %s", redir->word.gl_pathv[0]);
return 1;
}
} else {
close(openfd);
} else {
dup2(openfd, redir->fd);
- close(openfd);
+ if (redir->dup == -1)
+ close (openfd);
}
}
}
}
}
-/* XXX this definitely needs some more thought, work, and
- * cribbing from other shells */
-static int pipe_wait(struct pipe *pi)
-{
- int rcode=0, i, pid, running, status;
- running = pi->num_progs;
- while (running) {
- pid=waitpid(-1, &status, 0);
- if (pid < 0) perror_msg_and_die("waitpid");
- for (i=0; i < pi->num_progs; i++) {
- if (pi->progs[i].pid == pid) {
- if (i==pi->num_progs-1) rcode=WEXITSTATUS(status);
- pi->progs[i].pid = 0;
- running--;
- break;
- }
- }
- }
- return rcode;
-}
-
-/* very simple version for testing */
+/* never returns */
+/* XXX no exit() here. If you don't exec, use _exit instead.
+ * The at_exit handlers apparently confuse the calling process,
+ * in particular stdin handling. Not sure why? */
static void pseudo_exec(struct child_prog *child)
{
- int rcode;
+ int i, rcode;
struct built_in_command *x;
if (child->argv) {
+ for (i=0; is_assignment(child->argv[i]); i++) {
+ debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
+ putenv(strdup(child->argv[i]));
+ }
+ child->argv+=i; /* XXX this hack isn't so horrible, since we are about
+ to exit, and therefore don't need to keep data
+ structures consistent for free() use. */
+ /* If a variable is assigned in a forest, and nobody listens,
+ * was it ever really set?
+ */
+ if (child->argv[0] == NULL) {
+ _exit(EXIT_SUCCESS);
+ }
+
/*
* Check if the command matches any of the builtins.
* Depending on context, this might be redundant. But it's
for (x = bltins; x->cmd; x++) {
if (strcmp(child->argv[0], x->cmd) == 0 ) {
debug_printf("builtin exec %s\n", child->argv[0]);
- exit(x->function(child));
+ rcode = x->function(child);
+ fflush(stdout);
+ _exit(rcode);
}
}
#endif
debug_printf("exec of %s\n",child->argv[0]);
execvp(child->argv[0],child->argv);
- perror("execvp");
- exit(1);
+ perror_msg("couldn't exec: %s",child->argv[0]);
+ _exit(1);
} else if (child->group) {
debug_printf("runtime nesting to group\n");
interactive=0; /* crucial!!!! */
rcode = run_list_real(child->group);
- /* OK to leak memory by not calling run_list_test,
+ /* OK to leak memory by not calling free_pipe_list,
* since this process is about to exit */
- exit(rcode);
+ _exit(rcode);
} else {
/* Can happen. See what bash does with ">foo" by itself. */
debug_printf("trying to pseudo_exec null command\n");
- exit(EXIT_SUCCESS);
+ _exit(EXIT_SUCCESS);
}
}
/* Linear search for the ID of the job to use */
pi->jobid = 1;
- for (thejob = job_list->head; thejob; thejob = thejob->next)
+ for (thejob = job_list; thejob; thejob = thejob->next)
if (thejob->jobid >= pi->jobid)
pi->jobid = thejob->jobid + 1;
/* add thejob to the list of running jobs */
- if (!job_list->head) {
- thejob = job_list->head = xmalloc(sizeof(*thejob));
+ if (!job_list) {
+ thejob = job_list = xmalloc(sizeof(*thejob));
} else {
- for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */;
+ for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
thejob->next = xmalloc(sizeof(*thejob));
thejob = thejob->next;
}
thejob->next = NULL;
thejob->running_progs = thejob->num_progs;
thejob->stopped_progs = 0;
- thejob->text = xmalloc(MAX_LINE);
+ thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
//if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0])
{
to the list of backgrounded thejobs and leave it alone */
printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
last_bg_pid = thejob->progs[0].pid;
+ last_jobid = thejob->jobid;
}
-/* remove a backgrounded job from a jobset */
+/* remove a backgrounded job */
static void remove_bg_job(struct pipe *pi)
{
struct pipe *prev_pipe;
- free_pipe(pi);
- if (pi == job_list->head) {
- job_list->head = pi->next;
+ if (pi == job_list) {
+ job_list = pi->next;
} else {
- prev_pipe = job_list->head;
+ prev_pipe = job_list;
while (prev_pipe->next != pi)
prev_pipe = prev_pipe->next;
prev_pipe->next = pi->next;
}
+ if (job_list)
+ last_jobid = job_list->jobid;
+ else
+ last_jobid = 0;
+ pi->stopped_progs = 0;
+ free_pipe(pi, 0);
free(pi);
}
-/* free up all memory from a pipe */
-static void free_pipe(struct pipe *pi)
-{
- int i;
-
- for (i = 0; i < pi->num_progs; i++) {
- free(pi->progs[i].argv);
- if (pi->progs[i].redirects)
- free(pi->progs[i].redirects);
- }
- if (pi->progs)
- free(pi->progs);
- if (pi->text)
- free(pi->text);
- if (pi->cmdbuf)
- free(pi->cmdbuf);
- memset(pi, 0, sizeof(struct pipe));
-}
-
-
-/* Checks to see if any background processes have exited -- if they
+/* Checks to see if any processes have exited -- if they
have, figure out why and see if a job has completed */
-static void checkjobs()
+static int checkjobs(struct pipe* fg_pipe)
{
+ int attributes;
int status;
int prognum = 0;
struct pipe *pi;
pid_t childpid;
- while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
- for (pi = job_list->head; pi; pi = pi->next) {
+ attributes = WUNTRACED;
+ if (fg_pipe==NULL) {
+ attributes |= WNOHANG;
+ }
+
+ while ((childpid = waitpid(-1, &status, attributes)) > 0) {
+ if (fg_pipe) {
+ int i, rcode = 0;
+ for (i=0; i < fg_pipe->num_progs; i++) {
+ if (fg_pipe->progs[i].pid == childpid) {
+ if (i==fg_pipe->num_progs-1)
+ rcode=WEXITSTATUS(status);
+ (fg_pipe->num_progs)--;
+ return(rcode);
+ }
+ }
+ }
+
+ for (pi = job_list; pi; pi = pi->next) {
prognum = 0;
- while (prognum < pi->num_progs &&
- pi->progs[prognum].pid != childpid) prognum++;
+ while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
+ prognum++;
+ }
if (prognum < pi->num_progs)
break;
}
+ if(pi==NULL) {
+ debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
+ continue;
+ }
+
if (WIFEXITED(status) || WIFSIGNALED(status)) {
/* child exited */
pi->running_progs--;
remove_bg_job(pi);
}
} else {
- if(pi==NULL)
- break;
/* child stopped */
pi->stopped_progs++;
pi->progs[prognum].is_stopped = 1;
+#if 0
+ /* Printing this stuff is a pain, since it tends to
+ * overwrite the prompt an inconveinient moments. So
+ * don't do that. */
if (pi->stopped_progs == pi->num_progs) {
- printf(JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
+ printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
}
+#endif
}
}
perror_msg("waitpid");
/* move the shell to the foreground */
- if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
- perror_msg("tcsetpgrp");
+ //if (interactive && tcsetpgrp(shell_terminal, getpgid(0)))
+ // perror_msg("tcsetpgrp-2");
+ return -1;
+}
+
+/* Figure out our controlling tty, checking in order stderr,
+ * stdin, and stdout. If check_pgrp is set, also check that
+ * we belong to the foreground process group associated with
+ * that tty. The value of shell_terminal is needed in order to call
+ * tcsetpgrp(shell_terminal, ...); */
+void controlling_tty(int check_pgrp)
+{
+ pid_t curpgrp;
+
+ if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
+ && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
+ && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
+ goto shell_terminal_error;
+
+ if (check_pgrp && curpgrp != getpgid(0))
+ goto shell_terminal_error;
+
+ return;
+
+shell_terminal_error:
+ shell_terminal = -1;
+ return;
}
/* run_pipe_real() starts all the jobs, but doesn't wait for anything
- * to finish. See pipe_wait().
+ * to finish. See checkjobs().
*
* return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
static int run_pipe_real(struct pipe *pi)
{
int i;
- int ctty;
int nextin, nextout;
int pipefds[2]; /* pipefds[0] is for reading */
struct child_prog *child;
struct built_in_command *x;
- ctty = -1;
nextin = 0;
- pi->pgrp = 0;
-
- /* Check if we are supposed to run in the foreground */
- if (interactive && pi->followup!=PIPE_BG) {
- if ((pi->pgrp = tcgetpgrp(ctty = 2)) < 0
- && (pi->pgrp = tcgetpgrp(ctty = 0)) < 0
- && (pi->pgrp = tcgetpgrp(ctty = 1)) < 0)
- return errno = ENOTTY, -1;
-
- if (pi->pgrp < 0 && pi->pgrp != getpgrp())
- return errno = EPERM, -1;
- }
+ pi->pgrp = -1;
/* Check if this is a simple builtin (not part of a pipe).
* Builtins within pipes have to fork anyway, and are handled in
* pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
*/
- if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
- child = & (pi->progs[0]);
- if (child->group && ! child->subshell) {
- int squirrel[] = {-1, -1, -1};
- int rcode;
- debug_printf("non-subshell grouping\n");
- setup_redirects(child, squirrel);
- /* XXX could we merge code with following builtin case,
- * by creating a pseudo builtin that calls run_list_real? */
- rcode = run_list_real(child->group);
- restore_redirects(squirrel);
- return rcode;
+ if (pi->num_progs == 1) child = & (pi->progs[0]);
+ if (pi->num_progs == 1 && child->group && child->subshell == 0) {
+ int squirrel[] = {-1, -1, -1};
+ int rcode;
+ debug_printf("non-subshell grouping\n");
+ setup_redirects(child, squirrel);
+ /* XXX could we merge code with following builtin case,
+ * by creating a pseudo builtin that calls run_list_real? */
+ rcode = run_list_real(child->group);
+ restore_redirects(squirrel);
+ return rcode;
+ } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
+ for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
+ if (i!=0 && child->argv[i]==NULL) {
+ /* assignments, but no command: set the local environment */
+ for (i=0; child->argv[i]!=NULL; i++) {
+
+ /* Ok, this case is tricky. We have to decide if this is a
+ * local variable, or an already exported variable. If it is
+ * already exported, we have to export the new value. If it is
+ * not exported, we need only set this as a local variable.
+ * This junk is all to decide whether or not to export this
+ * variable. */
+ int export_me=0;
+ char *name, *value;
+ name = xstrdup(child->argv[i]);
+ debug_printf("Local environment set: %s\n", name);
+ value = strchr(name, '=');
+ if (value)
+ *value=0;
+ if ( get_local_var(name)) {
+ export_me=1;
+ }
+ free(name);
+ set_local_var(child->argv[i], export_me);
+ }
+ return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
}
for (x = bltins; x->cmd; x++) {
- if (strcmp(child->argv[0], x->cmd) == 0 ) {
+ if (strcmp(child->argv[i], x->cmd) == 0 ) {
int squirrel[] = {-1, -1, -1};
int rcode;
- if (x->function == builtin_exec && child->argv[1]==NULL) {
+ if (x->function == builtin_exec && child->argv[i+1]==NULL) {
debug_printf("magic exec\n");
setup_redirects(child,NULL);
return EXIT_SUCCESS;
* Is it really safe for inline use? Experimentally,
* things seem to work with glibc. */
setup_redirects(child, squirrel);
+ for (i=0; is_assignment(child->argv[i]); i++) {
+ putenv(strdup(child->argv[i]));
+ }
+ child->argv+=i; /* XXX horrible hack */
rcode = x->function(child);
+ child->argv-=i; /* XXX restore hack so free() can work right */
restore_redirects(squirrel);
return rcode;
}
/* XXX test for failed fork()? */
if (!(child->pid = fork())) {
-
+ /* Set the handling for job control signals back to the default. */
+ signal(SIGINT, SIG_DFL);
+ signal(SIGQUIT, SIG_DFL);
+ signal(SIGTERM, SIG_DFL);
+ signal(SIGTSTP, SIG_DFL);
+ signal(SIGTTIN, SIG_DFL);
signal(SIGTTOU, SIG_DFL);
+ signal(SIGCHLD, SIG_DFL);
close_all();
/* Like bash, explicit redirects override pipes,
* and the pipe fd is available for dup'ing. */
setup_redirects(child,NULL);
-
- if (pi->followup!=PIPE_BG) {
- /* Put our child in the process group whose leader is the
- * first process in this pipe. */
+
+ if (interactive && pi->followup!=PIPE_BG) {
+ /* If we (the child) win the race, put ourselves in the process
+ * group whose leader is the first process in this pipe. */
if (pi->pgrp < 0) {
- pi->pgrp = child->pid;
+ pi->pgrp = getpid();
}
- /* Don't check for errors. The child may be dead already,
- * in which case setpgid returns error code EACCES. */
if (setpgid(0, pi->pgrp) == 0) {
- signal(SIGTTOU, SIG_IGN);
- tcsetpgrp(ctty, pi->pgrp);
- signal(SIGTTOU, SIG_DFL);
+ tcsetpgrp(2, pi->pgrp);
}
}
pseudo_exec(child);
}
- /* Put our child in the process group whose leader is the
- * first process in this pipe. */
+
+
+ /* put our child in the process group whose leader is the
+ first process in this pipe */
if (pi->pgrp < 0) {
pi->pgrp = child->pid;
}
if (rmode == RES_ELIF && !if_code) continue;
if (pi->num_progs == 0) continue;
rcode = run_pipe_real(pi);
+ debug_printf("run_pipe_real returned %d\n",rcode);
if (rcode!=-1) {
/* We only ran a builtin: rcode was set by the return value
* of run_pipe_real(), and we don't need to wait for anything. */
insert_bg_job(pi);
rcode = EXIT_SUCCESS;
} else {
-
if (interactive) {
/* move the new process group into the foreground */
- /* suppress messages when run from /linuxrc mag@sysgo.de */
- //signal(SIGTTIN, SIG_IGN);
- //signal(SIGTTOU, SIG_IGN);
- if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY)
- perror_msg("tcsetpgrp");
- rcode = pipe_wait(pi);
- if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY)
- perror_msg("tcsetpgrp");
- //signal(SIGTTIN, SIG_DFL);
- //signal(SIGTTOU, SIG_DFL);
+ if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
+ perror_msg("tcsetpgrp-3");
+ rcode = checkjobs(pi);
+ /* move the shell to the foreground */
+ if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
+ perror_msg("tcsetpgrp-4");
} else {
- rcode = pipe_wait(pi);
+ rcode = checkjobs(pi);
}
+ debug_printf("checkjobs returned %d\n",rcode);
}
last_return_code=rcode;
if ( rmode == RES_IF || rmode == RES_ELIF )
if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
(rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
skip_more_in_this_rmode=rmode;
- /* return rcode; */ /* XXX broken if list is part of if/then/else */
+ checkjobs(NULL);
}
- checkjobs();
return rcode;
}
}
/* return code is the exit status of the pipe */
-static int run_pipe_test(struct pipe *pi, int indent)
+static int free_pipe(struct pipe *pi, int indent)
{
char **p;
struct child_prog *child;
struct redir_struct *r, *rnext;
int a, i, ret_code=0;
char *ind = indenter(indent);
+
+ if (pi->stopped_progs > 0)
+ return ret_code;
final_printf("%s run pipe: (pid %d)\n",ind,getpid());
for (i=0; i<pi->num_progs; i++) {
child = &pi->progs[i];
child->argv=NULL;
} else if (child->group) {
final_printf("%s begin group (subshell:%d)\n",ind, child->subshell);
- ret_code = run_list_test(child->group,indent+3);
+ ret_code = free_pipe_list(child->group,indent+3);
final_printf("%s end group\n",ind);
} else {
final_printf("%s (nil)\n",ind);
for (r=child->redirects; r; r=rnext) {
final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
if (r->dup == -1) {
- final_printf(" %s\n", *r->word.gl_pathv);
- globfree(&r->word);
+ /* guard against the case >$FOO, where foo is unset or blank */
+ if (r->word.gl_pathv) {
+ final_printf(" %s\n", *r->word.gl_pathv);
+ globfree(&r->word);
+ }
} else {
final_printf("&%d\n", r->dup);
}
return ret_code;
}
-static int run_list_test(struct pipe *head, int indent)
+static int free_pipe_list(struct pipe *head, int indent)
{
int rcode=0; /* if list has no members */
struct pipe *pi, *next;
char *ind = indenter(indent);
for (pi=head; pi; pi=next) {
- if (pi->num_progs == 0) break;
final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
- rcode = run_pipe_test(pi, indent);
+ rcode = free_pipe(pi, indent);
final_printf("%s pipe followup code %d\n", ind, pi->followup);
next=pi->next;
pi->next=NULL;
if (fake_mode==0) {
rcode = run_list_real(pi);
}
- /* run_list_test has the side effect of clearing memory
+ /* free_pipe_list has the side effect of clearing memory
* In the long run that function can be merged with run_list_real,
* but doing that now would hobble the debugging effort. */
- run_list_test(pi,0);
+ free_pipe_list(pi,0);
return rcode;
}
*/
static int globhack(const char *src, int flags, glob_t *pglob)
{
- int cnt, pathc;
+ int cnt=0, pathc;
const char *s;
char *dest;
- for (cnt=1, s=src; *s; s++) {
+ for (cnt=1, s=src; s && *s; s++) {
if (*s == '\\') s++;
cnt++;
}
if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
pglob->gl_pathv[pathc-1]=dest;
pglob->gl_pathv[pathc]=NULL;
- for (s=src; *s; s++, dest++) {
+ for (s=src; s && *s; s++, dest++) {
if (*s == '\\') s++;
*dest = *s;
}
gr = globhack(dest->data, flags, pglob);
debug_printf("globhack returned %d\n",gr);
}
- if (gr == GLOB_NOSPACE) {
- fprintf(stderr,"out of memory during glob\n");
- exit(1);
- }
+ if (gr == GLOB_NOSPACE)
+ error_msg_and_die("out of memory during glob");
if (gr != 0) { /* GLOB_ABORTED ? */
- fprintf(stderr,"glob(3) error %d\n",gr);
+ error_msg("glob(3) error %d",gr);
}
/* globprint(glob_target); */
return gr;
}
+/* This is used to get/check local shell variables */
+static char *get_local_var(const char *s)
+{
+ struct variables *cur;
+
+ if (!s)
+ return NULL;
+ for (cur = top_vars; cur; cur=cur->next)
+ if(strcmp(cur->name, s)==0)
+ return cur->value;
+ return NULL;
+}
+
+/* This is used to set local shell variables
+ flg_export==0 if only local (not exporting) variable
+ flg_export==1 if "new" exporting environ
+ flg_export>1 if current startup environ (not call putenv()) */
+static int set_local_var(const char *s, int flg_export)
+{
+ char *name, *value;
+ int result=0;
+ struct variables *cur;
+
+ name=strdup(s);
+
+ /* Assume when we enter this function that we are already in
+ * NAME=VALUE format. So the first order of business is to
+ * split 's' on the '=' into 'name' and 'value' */
+ value = strchr(name, '=');
+ if (value==0 && ++value==0) {
+ free(name);
+ return -1;
+ }
+ *value++ = 0;
+
+ for(cur = top_vars; cur; cur = cur->next) {
+ if(strcmp(cur->name, name)==0)
+ break;
+ }
+
+ if(cur) {
+ if(strcmp(cur->value, value)==0) {
+ if(flg_export>0 && cur->flg_export==0)
+ cur->flg_export=flg_export;
+ else
+ result++;
+ } else {
+ if(cur->flg_read_only) {
+ error_msg("%s: readonly variable", name);
+ result = -1;
+ } else {
+ if(flg_export>0 || cur->flg_export>1)
+ cur->flg_export=1;
+ free(cur->value);
+
+ cur->value = strdup(value);
+ }
+ }
+ } else {
+ cur = malloc(sizeof(struct variables));
+ if(!cur) {
+ result = -1;
+ } else {
+ cur->name = strdup(name);
+ if(cur->name == 0) {
+ free(cur);
+ result = -1;
+ } else {
+ struct variables *bottom = top_vars;
+ cur->value = strdup(value);
+ cur->next = 0;
+ cur->flg_export = flg_export;
+ cur->flg_read_only = 0;
+ while(bottom->next) bottom=bottom->next;
+ bottom->next = cur;
+ }
+ }
+ }
+
+ if(result==0 && cur->flg_export==1) {
+ *(value-1) = '=';
+ result = putenv(name);
+ } else {
+ free(name);
+ if(result>0) /* equivalent to previous set */
+ result = 0;
+ }
+ return result;
+}
+
+static void unset_local_var(const char *name)
+{
+ struct variables *cur;
+
+ if (name) {
+ for (cur = top_vars; cur; cur=cur->next) {
+ if(strcmp(cur->name, name)==0)
+ break;
+ }
+ if(cur!=0) {
+ struct variables *next = top_vars;
+ if(cur->flg_read_only) {
+ error_msg("%s: readonly variable", name);
+ return;
+ } else {
+ if(cur->flg_export)
+ unsetenv(cur->name);
+ free(cur->name);
+ free(cur->value);
+ while (next->next != cur)
+ next = next->next;
+ next->next = cur->next;
+ }
+ free(cur);
+ }
+ }
+}
+
+static int is_assignment(const char *s)
+{
+ if (s==NULL || !isalpha(*s)) return 0;
+ ++s;
+ while(isalnum(*s) || *s=='_') ++s;
+ return *s=='=';
+}
+
/* the src parameter allows us to peek forward to a possible &n syntax
* for file descriptor duplication, e.g., "2>&1".
* Return code is 0 normally, 1 if a syntax error is detected in src.
}
redir = xmalloc(sizeof(struct redir_struct));
redir->next=NULL;
+ redir->word.gl_pathv=NULL;
if (last_redir) {
last_redir->next=redir;
} else {
debug_printf("pop stack\n");
old = ctx->stack;
old->child->group = ctx->list_head;
+ old->child->subshell = 0;
*ctx = *old; /* physical copy */
free(old);
}
if (ctx->pending_redirect) {
ctx->pending_redirect=NULL;
if (glob_target->gl_pathc != 1) {
- fprintf(stderr, "ambiguous redirect\n");
+ error_msg("ambiguous redirect");
return 1;
}
} else {
}
if (ok) return d;
- fprintf(stderr, "ambiguous redirect\n");
+ error_msg("ambiguous redirect");
return -2;
}
#if 0
#define SURROGATE "surrogate response"
write(1,SURROGATE,sizeof(SURROGATE));
- exit(run_list(head));
+ _exit(run_list(head));
#else
- exit(run_list_real(head)); /* leaks memory */
+ _exit(run_list_real(head)); /* leaks memory */
#endif
}
debug_printf("forked child %d\n",pid);
pf = fdopen(channel[0],"r");
debug_printf("pipe on FILE *%p\n",pf);
#else
- run_list_test(head,0);
+ free_pipe_list(head,0);
pf=popen("echo surrogate response","r");
debug_printf("started fake pipe on FILE *%p\n",pf);
#endif
* to the KISS philosophy of this program. */
mark_closed(fileno(p));
retcode=pclose(p);
+ free_pipe_list(inner.list_head,0);
debug_printf("pclosed, retcode=%d\n",retcode);
/* XXX this process fails to trim a single trailing newline */
return retcode;
static void lookup_param(o_string *dest, struct p_context *ctx, o_string *src)
{
const char *p=NULL;
- if (src->data) p = getenv(src->data);
+ if (src->data) {
+ p = getenv(src->data);
+ if (!p)
+ p = get_local_var(src->data);
+ }
if (p) parse_string(dest, ctx, p); /* recursion */
b_free(src);
}
case '-':
case '_':
/* still unhandled, but should be eventually */
- fprintf(stderr,"unhandled syntax: $%c\n",ch);
+ error_msg("unhandled syntax: $%c",ch);
return 1;
break;
default:
done_pipe(ctx,PIPE_SEQ);
}
if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
- debug_printf("leaving parse_stream\n");
+ debug_printf("leaving parse_stream (triggered)\n");
return 0;
}
#if 0
* that is, we were really supposed to get end_trigger, and never got
* one before the EOF. Can't use the standard "syntax error" return code,
* so that parse_stream_outer can distinguish the EOF and exit smoothly. */
+ debug_printf("leaving parse_stream (EOF)\n");
if (end_trigger != '\0') return -1;
return 0;
}
* The map[] array only really needs two bits each, and on most machines
* that would be faster because of the reduced L1 cache footprint.
*/
- memset(map,0,256); /* most characters flow through always */
- mapset("\\$'\"`", 3); /* never flow through */
- mapset("<>;&|(){}#", 1); /* flow through if quoted */
- mapset(ifs, 2); /* also flow through if quoted */
+ memset(map,0,sizeof(map)); /* most characters flow through always */
+ mapset("\\$'\"`", 3); /* never flow through */
+ mapset("<>;&|(){}#", 1); /* flow through if quoted */
+ mapset(ifs, 2); /* also flow through if quoted */
}
/* most recursion does not come through here, the exeception is
done_word(&temp, &ctx);
done_pipe(&ctx,PIPE_SEQ);
run_list(ctx.list_head);
+ b_free(&temp);
} while (rcode != -1); /* loop on syntax errors, return on EOF */
return 0;
}
return rcode;
}
+/* Make sure we have a controlling tty. If we get started under a job
+ * aware app (like bash for example), make sure we are now in charge so
+ * we don't fight over who gets the foreground */
+static void setup_job_control()
+{
+ static pid_t shell_pgrp;
+ /* Loop until we are in the foreground. */
+ while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
+ kill (- shell_pgrp, SIGTTIN);
+
+ /* Ignore interactive and job-control signals. */
+ signal(SIGINT, SIG_IGN);
+ signal(SIGQUIT, SIG_IGN);
+ signal(SIGTERM, SIG_IGN);
+ signal(SIGTSTP, SIG_IGN);
+ signal(SIGTTIN, SIG_IGN);
+ signal(SIGTTOU, SIG_IGN);
+ signal(SIGCHLD, SIG_IGN);
+
+ /* Put ourselves in our own process group. */
+ setsid();
+ shell_pgrp = getpid ();
+ setpgid (shell_pgrp, shell_pgrp);
+
+ /* Grab control of the terminal. */
+ tcsetpgrp(shell_terminal, shell_pgrp);
+}
+
int shell_main(int argc, char **argv)
{
int opt;
FILE *input;
- struct jobset joblist_end = { NULL, NULL };
- job_list = &joblist_end;
-
- last_return_code=EXIT_SUCCESS;
+ char **e = environ;
/* XXX what should these be while sourcing /etc/profile? */
global_argc = argc;
global_argv = argv;
-
- /* don't pay any attention to this signal; it just confuses
- things and isn't really meant for shells anyway */
- signal(SIGTTOU, SIG_IGN);
-
- if (argv[0] && argv[0][0] == '-') {
- debug_printf("\nsourcing /etc/profile\n");
- input = xfopen("/etc/profile", "r");
- mark_open(fileno(input));
- parse_file_outer(input);
- mark_closed(fileno(input));
- fclose(input);
- }
- input=stdin;
- /* initialize the cwd -- this is never freed...*/
- cwd = xgetcwd(0);
- if (!cwd)
- cwd = unknown;
+ /* (re?) initialize globals. Sometimes shell_main() ends up calling
+ * shell_main(), therefore we cannot rely on the BSS to zero out this
+ * stuff. Reset these to 0 every time. */
+ ifs = NULL;
+ /* map[] is taken care of with call to update_ifs_map() */
+ fake_mode = 0;
+ interactive = 0;
+ close_me_head = NULL;
+ last_bg_pid = 0;
+ job_list = NULL;
+ last_jobid = 0;
+
+ /* Initialize some more globals to non-zero values */
+ set_cwd();
#ifdef BB_FEATURE_COMMAND_EDITING
cmdedit_set_initial_prompt();
#else
PS1 = NULL;
#endif
+ PS2 = "> ";
+
+ /* initialize our shell local variables with the values
+ * currently living in the environment */
+ if (e) {
+ for (; *e; e++)
+ set_local_var(*e, 2); /* without call putenv() */
+ }
+
+ last_return_code=EXIT_SUCCESS;
+
+
+ if (argv[0] && argv[0][0] == '-') {
+ debug_printf("\nsourcing /etc/profile\n");
+ if ((input = fopen("/etc/profile", "r")) != NULL) {
+ mark_open(fileno(input));
+ parse_file_outer(input);
+ mark_closed(fileno(input));
+ fclose(input);
+ }
+ }
+ input=stdin;
while ((opt = getopt(argc, argv, "c:xif")) > 0) {
switch (opt) {
fake_mode++;
break;
default:
+#ifndef BB_VER
fprintf(stderr, "Usage: sh [FILE]...\n"
" or: sh -c command [args]...\n\n");
exit(EXIT_FAILURE);
+#else
+ show_usage();
+#endif
}
}
/* A shell is interactive if the `-i' flag was given, or if all of
if (interactive) {
/* Looks like they want an interactive shell */
fprintf(stdout, "\nhush -- the humble shell v0.01 (testing)\n\n");
+ setup_job_control();
+ }
+
+ if (argv[optind]==NULL) {
opt=parse_file_outer(stdin);
goto final_return;
}
opt = parse_file_outer(input);
#ifdef BB_FEATURE_CLEAN_UP
- fclose(input.file);
+ fclose(input);
+ if (cwd && cwd != unknown)
+ free((char*)cwd);
+ {
+ struct variables *cur, *tmp;
+ for(cur = top_vars; cur; cur = tmp) {
+ tmp = cur->next;
+ if (!cur->flg_read_only) {
+ free(cur->name);
+ free(cur->value);
+ free(cur);
+ }
+ }
+ }
#endif
final_return:
projects / oweals / busybox.git / blobdiff