This patch covers one big part of variable handling.
$ a=b foo
should be handled correctly.
$ a=b
is parsed OK, but the actual variable setting is not
yet written. Except for some weird exceptions related
to quoting rules, this code passes (matches ash behavior)
all the tests I threw at it.
If someone now writes set_local_var(), and updates lookup_param()
to match, we can claim success!
- Larry
This commit is contained in:
Eric Andersen
parent
be9f44a7df
commit
78a7c99f7f
54
hush.c
54
hush.c
@ -43,6 +43,7 @@
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* Brace Expansion
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* Tilde Expansion
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* fancy forms of Parameter Expansion
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* aliases
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* Arithmetic Expansion
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* <(list) and >(list) Process Substitution
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* reserved words: case, esac, select, function
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@ -54,15 +55,14 @@
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* to-do:
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* port selected bugfixes from post-0.49 busybox lash - done?
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* finish implementing reserved words: for, while, until, do, done
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* finish implementing local variable assignment
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* change { and } from special chars to reserved words
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* builtins: break, continue, eval, return, set, trap, ulimit
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* test magic exec
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* handle children going into background
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* clean up recognition of null pipes
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* have builtin_exec set flag to avoid restore_redirects
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* check setting of global_argc and global_argv
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* control-C handling, probably with longjmp
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* VAR=value prefix for simple commands
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* follow IFS rules more precisely, including update semantics
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* figure out what to do with backslash-newline
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* explain why we use signal instead of sigaction
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@ -70,6 +70,7 @@
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* continuation lines, both explicit and implicit - done?
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* memory leak finding and plugging - done?
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* more testing, especially quoting rules and redirection
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* document how quoting rules not precisely followed for variable assignments
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* maybe change map[] to use 2-bit entries
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* (eventually) remove all the printf's
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*
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@ -359,6 +360,9 @@ static int run_pipe_real(struct pipe *pi);
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static int globhack(const char *src, int flags, glob_t *pglob);
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static int glob_needed(const char *s);
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static int xglob(o_string *dest, int flags, glob_t *pglob);
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/* variable assignment: */
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static int set_local_var(const char *s);
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static int is_assignment(const char *s);
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/* data structure manipulation: */
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static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
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static void initialize_context(struct p_context *ctx);
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@ -1001,9 +1005,20 @@ static int pipe_wait(struct pipe *pi)
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/* very simple version for testing */
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static void pseudo_exec(struct child_prog *child)
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{
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int rcode;
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int i, rcode;
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struct built_in_command *x;
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if (child->argv) {
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for (i=0; is_assignment(child->argv[i]); i++) {
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putenv(strdup(child->argv[i]));
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}
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child->argv+=i; /* XXX this hack isn't so horrible, since we are about
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to exit, and therefore don't need to keep data
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structures consistent for free() use. */
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/* If a variable is assigned in a forest, and nobody listens,
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* was it ever really set?
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*/
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if (child->argv[0] == NULL) exit(EXIT_SUCCESS);
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/*
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* Check if the command matches any of the builtins.
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* Depending on context, this might be redundant. But it's
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@ -1253,11 +1268,19 @@ static int run_pipe_real(struct pipe *pi)
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restore_redirects(squirrel);
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return rcode;
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}
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for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
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if (i!=0 && child->argv[i]==NULL) {
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/* assignments, but no command: set the local environment */
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for (i=0; child->argv[i]!=NULL; i++) {
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set_local_var(child->argv[i]);
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}
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return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
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}
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for (x = bltins; x->cmd; x++) {
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if (strcmp(child->argv[0], x->cmd) == 0 ) {
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if (strcmp(child->argv[i], x->cmd) == 0 ) {
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int squirrel[] = {-1, -1, -1};
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int rcode;
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if (x->function == builtin_exec && child->argv[1]==NULL) {
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if (x->function == builtin_exec && child->argv[i+1]==NULL) {
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debug_printf("magic exec\n");
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setup_redirects(child,NULL);
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return EXIT_SUCCESS;
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@ -1268,7 +1291,12 @@ static int run_pipe_real(struct pipe *pi)
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* Is it really safe for inline use? Experimentally,
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* things seem to work with glibc. */
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setup_redirects(child, squirrel);
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for (i=0; is_assignment(child->argv[i]); i++) {
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putenv(strdup(child->argv[i]));
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}
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child->argv+=i; /* XXX horrible hack */
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rcode = x->function(child);
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child->argv-=i; /* XXX restore hack so free() can work right */
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restore_redirects(squirrel);
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return rcode;
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}
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@ -1581,6 +1609,22 @@ static int xglob(o_string *dest, int flags, glob_t *pglob)
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return gr;
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}
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static int set_local_var(const char *s)
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{
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/* when you write this, also need to update lookup_param() */
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printf("assignment %s not handled: write me!\n",s);
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return 0;
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}
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static int is_assignment(const char *s)
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{
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if (s==NULL || !isalpha(*s)) return 0;
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++s;
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while(isalnum(*s) || *s=='_') ++s;
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return *s=='=';
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}
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/* the src parameter allows us to peek forward to a possible &n syntax
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* for file descriptor duplication, e.g., "2>&1".
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* Return code is 0 normally, 1 if a syntax error is detected in src.
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54
shell/hush.c
54
shell/hush.c
@ -43,6 +43,7 @@
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* Brace Expansion
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* Tilde Expansion
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* fancy forms of Parameter Expansion
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* aliases
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* Arithmetic Expansion
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* <(list) and >(list) Process Substitution
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* reserved words: case, esac, select, function
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@ -54,15 +55,14 @@
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* to-do:
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* port selected bugfixes from post-0.49 busybox lash - done?
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* finish implementing reserved words: for, while, until, do, done
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* finish implementing local variable assignment
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* change { and } from special chars to reserved words
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* builtins: break, continue, eval, return, set, trap, ulimit
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* test magic exec
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* handle children going into background
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* clean up recognition of null pipes
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* have builtin_exec set flag to avoid restore_redirects
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* check setting of global_argc and global_argv
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* control-C handling, probably with longjmp
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* VAR=value prefix for simple commands
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* follow IFS rules more precisely, including update semantics
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* figure out what to do with backslash-newline
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* explain why we use signal instead of sigaction
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@ -70,6 +70,7 @@
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* continuation lines, both explicit and implicit - done?
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* memory leak finding and plugging - done?
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* more testing, especially quoting rules and redirection
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* document how quoting rules not precisely followed for variable assignments
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* maybe change map[] to use 2-bit entries
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* (eventually) remove all the printf's
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*
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@ -359,6 +360,9 @@ static int run_pipe_real(struct pipe *pi);
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static int globhack(const char *src, int flags, glob_t *pglob);
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static int glob_needed(const char *s);
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static int xglob(o_string *dest, int flags, glob_t *pglob);
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/* variable assignment: */
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static int set_local_var(const char *s);
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static int is_assignment(const char *s);
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/* data structure manipulation: */
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static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
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static void initialize_context(struct p_context *ctx);
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@ -1001,9 +1005,20 @@ static int pipe_wait(struct pipe *pi)
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/* very simple version for testing */
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static void pseudo_exec(struct child_prog *child)
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{
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int rcode;
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int i, rcode;
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struct built_in_command *x;
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if (child->argv) {
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for (i=0; is_assignment(child->argv[i]); i++) {
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putenv(strdup(child->argv[i]));
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}
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child->argv+=i; /* XXX this hack isn't so horrible, since we are about
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to exit, and therefore don't need to keep data
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structures consistent for free() use. */
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/* If a variable is assigned in a forest, and nobody listens,
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* was it ever really set?
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*/
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if (child->argv[0] == NULL) exit(EXIT_SUCCESS);
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/*
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* Check if the command matches any of the builtins.
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* Depending on context, this might be redundant. But it's
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@ -1253,11 +1268,19 @@ static int run_pipe_real(struct pipe *pi)
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restore_redirects(squirrel);
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return rcode;
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}
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for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
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if (i!=0 && child->argv[i]==NULL) {
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/* assignments, but no command: set the local environment */
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for (i=0; child->argv[i]!=NULL; i++) {
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set_local_var(child->argv[i]);
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}
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return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
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}
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for (x = bltins; x->cmd; x++) {
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if (strcmp(child->argv[0], x->cmd) == 0 ) {
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if (strcmp(child->argv[i], x->cmd) == 0 ) {
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int squirrel[] = {-1, -1, -1};
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int rcode;
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if (x->function == builtin_exec && child->argv[1]==NULL) {
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if (x->function == builtin_exec && child->argv[i+1]==NULL) {
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debug_printf("magic exec\n");
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setup_redirects(child,NULL);
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return EXIT_SUCCESS;
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@ -1268,7 +1291,12 @@ static int run_pipe_real(struct pipe *pi)
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* Is it really safe for inline use? Experimentally,
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* things seem to work with glibc. */
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setup_redirects(child, squirrel);
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for (i=0; is_assignment(child->argv[i]); i++) {
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putenv(strdup(child->argv[i]));
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}
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child->argv+=i; /* XXX horrible hack */
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rcode = x->function(child);
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child->argv-=i; /* XXX restore hack so free() can work right */
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restore_redirects(squirrel);
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return rcode;
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}
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@ -1581,6 +1609,22 @@ static int xglob(o_string *dest, int flags, glob_t *pglob)
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return gr;
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}
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static int set_local_var(const char *s)
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{
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/* when you write this, also need to update lookup_param() */
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printf("assignment %s not handled: write me!\n",s);
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return 0;
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}
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static int is_assignment(const char *s)
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{
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if (s==NULL || !isalpha(*s)) return 0;
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++s;
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while(isalnum(*s) || *s=='_') ++s;
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return *s=='=';
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}
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/* the src parameter allows us to peek forward to a possible &n syntax
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* for file descriptor duplication, e.g., "2>&1".
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* Return code is 0 normally, 1 if a syntax error is detected in src.
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