More hush updates from Larry:

Update some comments.  Generate partial placeholders for the missing
    builtins.  Write builtin_umask.  Properly treat exec without arguments
    as a means to open/close files within the running script.  Implement
    "4<&-" that encodes for file descriptor closure.
This commit is contained in:
Eric Andersen 2001-05-07 17:59:25 +00:00
parent 7e1273edf7
commit 83a2ae2184
2 changed files with 108 additions and 38 deletions

73
hush.c
View File

@ -45,24 +45,25 @@
* fancy forms of Parameter Expansion
* Arithmetic Expansion
* <(list) and >(list) Process Substitution
* reserved words: case, esac, function
* reserved words: case, esac, select, function
* Here Documents ( << word )
* Functions
* Major bugs:
* job handling woefully incomplete and buggy
* reserved word execution woefully incomplete and buggy
* to-do:
* port selected bugfixes from post-0.49 busybox lash
* finish implementing reserved words
* port selected bugfixes from post-0.49 busybox lash - done?
* finish implementing reserved words: for, while, until, do, done
* change { and } from special chars to reserved words
* builtins: break, continue, eval, return, set, trap, ulimit
* test magic exec
* handle children going into background
* clean up recognition of null pipes
* have builtin_exec set flag to avoid restore_redirects
* figure out if "echo foo}" is fixable
* 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
* write builtin_eval, builtin_ulimit, builtin_umask
* figure out what to do with backslash-newline
* explain why we use signal instead of sigaction
* propagate syntax errors, die on resource errors?
@ -97,6 +98,7 @@
#include <fcntl.h>
#include <getopt.h> /* should be pretty obvious */
#include <sys/stat.h> /* ulimit */
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
@ -323,9 +325,9 @@ static int builtin_pwd(struct child_prog *child);
static int builtin_read(struct child_prog *child);
static int builtin_shift(struct child_prog *child);
static int builtin_source(struct child_prog *child);
static int builtin_ulimit(struct child_prog *child);
static int builtin_umask(struct child_prog *child);
static int builtin_unset(struct child_prog *child);
static int builtin_not_written(struct child_prog *child);
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
@ -390,8 +392,11 @@ static void free_pipe(struct pipe *pi);
* still be set at the end. */
static struct built_in_command bltins[] = {
{"bg", "Resume a job in the background", builtin_fg_bg},
{"break", "Exit for, while or until loop", builtin_not_written},
{"cd", "Change working directory", builtin_cd},
{"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},
{"exit", "Exit from shell()", builtin_exit},
{"export", "Set environment variable", builtin_export},
@ -399,8 +404,11 @@ static struct built_in_command bltins[] = {
{"jobs", "Lists the active jobs", builtin_jobs},
{"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},
{"shift", "Shift positional parameters", builtin_shift},
{"ulimit","Controls resource limits", builtin_ulimit},
{"trap", "Trap signals", builtin_not_written},
{"ulimit","Controls resource limits", builtin_not_written},
{"umask","Sets file creation mask", builtin_umask},
{"unset", "Unset environment variable", builtin_unset},
{".", "Source-in and run commands in a file", builtin_source},
@ -640,16 +648,21 @@ static int builtin_source(struct child_prog *child)
return (status);
}
static int builtin_ulimit(struct child_prog *child)
{
printf("builtin_ulimit not written\n");
return EXIT_FAILURE;
}
static int builtin_umask(struct child_prog *child)
{
printf("builtin_umask not written\n");
return EXIT_FAILURE;
mode_t new_umask;
const char *arg = child->argv[1];
char *end;
if (arg) {
new_umask=strtoul(arg, &end, 8);
if (*end!='\0' || end == arg) {
return EXIT_FAILURE;
}
} else {
printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
}
umask(new_umask);
return EXIT_SUCCESS;
}
/* built-in 'unset VAR' handler */
@ -663,6 +676,12 @@ static int builtin_unset(struct child_prog *child)
return EXIT_SUCCESS;
}
static int builtin_not_written(struct child_prog *child)
{
printf("builtin_%s not written\n",child->argv[0]);
return EXIT_FAILURE;
}
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
@ -926,8 +945,12 @@ static int setup_redirects(struct child_prog *prog, int squirrel[])
if (squirrel && redir->fd < 3) {
squirrel[redir->fd] = dup(redir->fd);
}
dup2(openfd, redir->fd);
close(openfd);
if (openfd == -3) {
close(openfd);
} else {
dup2(openfd, redir->fd);
close(openfd);
}
}
}
return 0;
@ -1216,6 +1239,11 @@ static int run_pipe_real(struct pipe *pi)
if (strcmp(child->argv[0], x->cmd) == 0 ) {
int squirrel[] = {-1, -1, -1};
int rcode;
if (x->function == builtin_exec && child->argv[1]==NULL) {
debug_printf("magic exec\n");
setup_redirects(child,NULL);
return EXIT_SUCCESS;
}
debug_printf("builtin inline %s\n", child->argv[0]);
/* XXX setup_redirects acts on file descriptors, not FILEs.
* This is perfect for work that comes after exec().
@ -1569,7 +1597,8 @@ static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
if (redir->dup == -2) return 1; /* syntax error */
if (redir->dup != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time" */
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* We do _not_ try to open the file that src points to,
@ -1775,10 +1804,16 @@ static int redirect_dup_num(struct in_str *input)
if (ch != '&') return -1;
b_getch(input); /* get the & */
while (ch=b_peek(input),isdigit(ch)) {
ch=b_peek(input);
if (ch == '-') {
b_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10+(ch-'0');
ok=1;
b_getch(input);
ch = b_peek(input);
}
if (ok) return d;

View File

@ -45,24 +45,25 @@
* fancy forms of Parameter Expansion
* Arithmetic Expansion
* <(list) and >(list) Process Substitution
* reserved words: case, esac, function
* reserved words: case, esac, select, function
* Here Documents ( << word )
* Functions
* Major bugs:
* job handling woefully incomplete and buggy
* reserved word execution woefully incomplete and buggy
* to-do:
* port selected bugfixes from post-0.49 busybox lash
* finish implementing reserved words
* port selected bugfixes from post-0.49 busybox lash - done?
* finish implementing reserved words: for, while, until, do, done
* change { and } from special chars to reserved words
* builtins: break, continue, eval, return, set, trap, ulimit
* test magic exec
* handle children going into background
* clean up recognition of null pipes
* have builtin_exec set flag to avoid restore_redirects
* figure out if "echo foo}" is fixable
* 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
* write builtin_eval, builtin_ulimit, builtin_umask
* figure out what to do with backslash-newline
* explain why we use signal instead of sigaction
* propagate syntax errors, die on resource errors?
@ -97,6 +98,7 @@
#include <fcntl.h>
#include <getopt.h> /* should be pretty obvious */
#include <sys/stat.h> /* ulimit */
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
@ -323,9 +325,9 @@ static int builtin_pwd(struct child_prog *child);
static int builtin_read(struct child_prog *child);
static int builtin_shift(struct child_prog *child);
static int builtin_source(struct child_prog *child);
static int builtin_ulimit(struct child_prog *child);
static int builtin_umask(struct child_prog *child);
static int builtin_unset(struct child_prog *child);
static int builtin_not_written(struct child_prog *child);
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
@ -390,8 +392,11 @@ static void free_pipe(struct pipe *pi);
* still be set at the end. */
static struct built_in_command bltins[] = {
{"bg", "Resume a job in the background", builtin_fg_bg},
{"break", "Exit for, while or until loop", builtin_not_written},
{"cd", "Change working directory", builtin_cd},
{"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},
{"exit", "Exit from shell()", builtin_exit},
{"export", "Set environment variable", builtin_export},
@ -399,8 +404,11 @@ static struct built_in_command bltins[] = {
{"jobs", "Lists the active jobs", builtin_jobs},
{"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},
{"shift", "Shift positional parameters", builtin_shift},
{"ulimit","Controls resource limits", builtin_ulimit},
{"trap", "Trap signals", builtin_not_written},
{"ulimit","Controls resource limits", builtin_not_written},
{"umask","Sets file creation mask", builtin_umask},
{"unset", "Unset environment variable", builtin_unset},
{".", "Source-in and run commands in a file", builtin_source},
@ -640,16 +648,21 @@ static int builtin_source(struct child_prog *child)
return (status);
}
static int builtin_ulimit(struct child_prog *child)
{
printf("builtin_ulimit not written\n");
return EXIT_FAILURE;
}
static int builtin_umask(struct child_prog *child)
{
printf("builtin_umask not written\n");
return EXIT_FAILURE;
mode_t new_umask;
const char *arg = child->argv[1];
char *end;
if (arg) {
new_umask=strtoul(arg, &end, 8);
if (*end!='\0' || end == arg) {
return EXIT_FAILURE;
}
} else {
printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
}
umask(new_umask);
return EXIT_SUCCESS;
}
/* built-in 'unset VAR' handler */
@ -663,6 +676,12 @@ static int builtin_unset(struct child_prog *child)
return EXIT_SUCCESS;
}
static int builtin_not_written(struct child_prog *child)
{
printf("builtin_%s not written\n",child->argv[0]);
return EXIT_FAILURE;
}
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
@ -926,8 +945,12 @@ static int setup_redirects(struct child_prog *prog, int squirrel[])
if (squirrel && redir->fd < 3) {
squirrel[redir->fd] = dup(redir->fd);
}
dup2(openfd, redir->fd);
close(openfd);
if (openfd == -3) {
close(openfd);
} else {
dup2(openfd, redir->fd);
close(openfd);
}
}
}
return 0;
@ -1216,6 +1239,11 @@ static int run_pipe_real(struct pipe *pi)
if (strcmp(child->argv[0], x->cmd) == 0 ) {
int squirrel[] = {-1, -1, -1};
int rcode;
if (x->function == builtin_exec && child->argv[1]==NULL) {
debug_printf("magic exec\n");
setup_redirects(child,NULL);
return EXIT_SUCCESS;
}
debug_printf("builtin inline %s\n", child->argv[0]);
/* XXX setup_redirects acts on file descriptors, not FILEs.
* This is perfect for work that comes after exec().
@ -1569,7 +1597,8 @@ static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
if (redir->dup == -2) return 1; /* syntax error */
if (redir->dup != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time" */
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* We do _not_ try to open the file that src points to,
@ -1775,10 +1804,16 @@ static int redirect_dup_num(struct in_str *input)
if (ch != '&') return -1;
b_getch(input); /* get the & */
while (ch=b_peek(input),isdigit(ch)) {
ch=b_peek(input);
if (ch == '-') {
b_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10+(ch-'0');
ok=1;
b_getch(input);
ch = b_peek(input);
}
if (ok) return d;