diff options
Diffstat (limited to 'shell/lash.c')
| -rw-r--r-- | shell/lash.c | 108 |
1 files changed, 71 insertions, 37 deletions
diff --git a/shell/lash.c b/shell/lash.c index b8ddc87..22a6967 100644 --- a/shell/lash.c +++ b/shell/lash.c @@ -26,7 +26,7 @@ */ // -//This works pretty well now, and is not on by default. +//This works pretty well now, and is now on by default. #define BB_FEATURE_SH_ENVIRONMENT // //Backtick support has some problems, use at your own risk! @@ -34,7 +34,7 @@ // //If, then, else, etc. support.. This should now behave basically //like any other Bourne shell... -//#define BB_FEATURE_SH_IF_EXPRESSIONS +#define BB_FEATURE_SH_IF_EXPRESSIONS // /* This is currently a little broken... */ //#define HANDLE_CONTINUATION_CHARS @@ -316,22 +316,23 @@ static int builtin_fg_bg(struct child_prog *child) int i, jobNum; struct job *job=NULL; + if (!child->argv[1] || child->argv[2]) { + error_msg("%s: exactly one argument is expected\n", + child->argv[0]); + return EXIT_FAILURE; + } - if (!child->argv[1] || child->argv[2]) { - error_msg("%s: exactly one argument is expected\n", - child->argv[0]); - return EXIT_FAILURE; - } - if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) { - error_msg("%s: bad argument '%s'\n", - child->argv[0], child->argv[1]); - return EXIT_FAILURE; - } - for (job = child->family->job_list->head; job; job = job->next) { - if (job->jobid == jobNum) { - break; - } + if (sscanf(child->argv[1], "%%%d", &jobNum) != 1) { + error_msg("%s: bad argument '%s'\n", + child->argv[0], child->argv[1]); + return EXIT_FAILURE; + } + + for (job = child->family->job_list->head; job; job = job->next) { + if (job->jobid == jobNum) { + break; } + } if (!job) { error_msg("%s: unknown job %d\n", @@ -524,7 +525,7 @@ static int builtin_else(struct child_prog *child) } cmd->job_context |= ELSE_EXP_CONTEXT; - debug_printf("job=%p builtin_else set job context to %x\n", child->family, cmd->job_context); + debug_printf("job=%p builtin_else set job context to %x\n", cmd, cmd->job_context); /* Now run the 'else' command */ debug_printf( "'else' now running '%s'\n", charptr1); @@ -583,12 +584,13 @@ static int builtin_unset(struct child_prog *child) #ifdef BB_FEATURE_SH_IF_EXPRESSIONS /* currently used by if/then/else. - * Needlessly (?) forks and reparses the command line. - * But pseudo_exec on the pre-parsed args doesn't have the - * "fork, stick around until the child exits, and find it's return code" - * functionality. The fork is not needed if the predicate is - * non-forking builtin, and maybe not even if it's a forking builtin. - * applets pretty clearly need the fork. + * + * Reparsing the command line for this purpose is gross, + * incorrect, and fundamentally unfixable; in particular, + * think about what happens with command substitution. + * We really need to pull out the run, wait, return status + * functionality out of busy_loop so we can child->argv++ + * and use that, without going back through parse_command. */ static int run_command_predicate(char *cmd) { @@ -684,7 +686,9 @@ static void checkjobs(struct jobset *job_list) perror("waitpid"); } -static int setup_redirects(struct child_prog *prog) +/* squirrel != NULL means we squirrel away copies of stdin, stdout, + * and stderr if they are redirected. */ +static int setup_redirects(struct child_prog *prog, int squirrel[]) { int i; int openfd; @@ -714,6 +718,9 @@ static int setup_redirects(struct child_prog *prog) } if (openfd != redir->fd) { + if (squirrel && redir->fd < 3) { + squirrel[redir->fd] = dup(redir->fd); + } dup2(openfd, redir->fd); close(openfd); } @@ -722,6 +729,19 @@ static int setup_redirects(struct child_prog *prog) return 0; } +static void restore_redirects(int squirrel[]) +{ + int i, fd; + for (i=0; i<3; i++) { + fd = squirrel[i]; + if (fd != -1) { + /* No error checking. I sure wouldn't know what + * to do with an error if I found one! */ + dup2(fd, i); + close(fd); + } + } +} static int get_command(FILE * source, char *command) { @@ -1304,11 +1324,18 @@ static int pseudo_exec(struct child_prog *child) struct BB_applet search_applet, *applet; #endif - /* Check if the command matches any of the forking builtins. - * XXX It would probably be wise to check for non-forking builtins - * here as well, since in some context the non-forking path - * is disabled or bypassed. See comment in run_command. + /* Check if the command matches any of the non-forking builtins. + * Depending on context, this might be redundant. But it's + * easier to waste a few CPU cycles than it is to figure out + * if this is one of those cases. */ + for (x = bltins; x->cmd; x++) { + if (strcmp(child->argv[0], x->cmd) == 0 ) { + exit(x->function(child)); + } + } + + /* Check if the command matches any of the forking builtins. */ for (x = bltins_forking; x->cmd; x++) { if (strcmp(child->argv[0], x->cmd) == 0) { applet_name=x->cmd; @@ -1435,15 +1462,22 @@ static int run_command(struct job *newjob, int inbg, int outpipe[2]) } #endif - /* Check if the command matches any non-forking builtins. - * XXX should probably skip this test, and fork anyway, if - * there redirects of some kind demand forking to work right. - * pseudo_exec would then need to handle the non-forking command - * in a forked context. + /* Check if the command matches any non-forking builtins, + * but only if this is a simple command. + * Non-forking builtins within pipes have to fork anyway, + * and are handled in pseudo_exec. "echo foo | read bar" + * is doomed to failure, and doesn't work on bash, either. */ - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[0], x->cmd) == 0 ) { - return(x->function(child)); + if (newjob->num_progs == 1) { + for (x = bltins; x->cmd; x++) { + if (strcmp(child->argv[0], x->cmd) == 0 ) { + int squirrel[] = {-1, -1, -1}; + int rcode; + setup_redirects(child, squirrel); + rcode = x->function(child); + restore_redirects(squirrel); + return rcode; + } } } @@ -1466,7 +1500,7 @@ static int run_command(struct job *newjob, int inbg, int outpipe[2]) } /* explicit redirects override pipes */ - setup_redirects(child); + setup_redirects(child,NULL); pseudo_exec(child); } |