Support disabling pipe and redirect support

shell/lash.c

@@ -56,14 +56,18 @@
 #include <glob.h>
 #define expand_t	glob_t
 
+/* Always enable for the moment... */
+#define CONFIG_LASH_PIPE_N_REDIRECTS
 
 static const int MAX_READ = 128;	/* size of input buffer for `read' builtin */
 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 
 
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
 enum redir_type { REDIRECT_INPUT, REDIRECT_OVERWRITE,
 	REDIRECT_APPEND
 };
+#endif
 
 static const unsigned int DEFAULT_CONTEXT=0x1;
 static const unsigned int IF_TRUE_CONTEXT=0x2;
@@ -71,25 +75,28 @@ static const unsigned int IF_FALSE_CONTEXT=0x4;
 static const unsigned int THEN_EXP_CONTEXT=0x8;
 static const unsigned int ELSE_EXP_CONTEXT=0x10;
 
-
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
-struct jobset {
-	struct job *head;			/* head of list of running jobs */
-	struct job *fg;				/* current foreground job */
-};
-
 struct redir_struct {
 	enum redir_type type;	/* type of redirection */
 	int fd;						/* file descriptor being redirected */
 	char *filename;				/* file to redirect fd to */
 };
+#endif
 
 struct child_prog {
 	pid_t pid;					/* 0 if exited */
 	char **argv;				/* program name and arguments */
 	int num_redirects;			/* elements in redirection array */
-	struct redir_struct *redirects;	/* I/O redirects */
 	int is_stopped;				/* is the program currently running? */
 	struct job *family;			/* pointer back to the child's parent job */
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
+	struct redir_struct *redirects;	/* I/O redirects */
+#endif
+};
+
+struct jobset {
+	struct job *head;			/* head of list of running jobs */
+	struct job *fg;				/* current foreground job */
 };
 
 struct job {
@@ -514,8 +521,10 @@ static void free_job(struct job *cmd)
 
 	for (i = 0; i < cmd->num_progs; i++) {
 		free(cmd->progs[i].argv);
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
 		if (cmd->progs[i].redirects)
 			free(cmd->progs[i].redirects);
+#endif
 	}
 	free(cmd->progs);
 	free(cmd->text);
@@ -601,6 +610,7 @@ static void checkjobs(struct jobset *j_list)
 		bb_perror_msg("waitpid");
 }
 
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
 /* 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[])
@@ -656,6 +666,15 @@ static void restore_redirects(int squirrel[])
 		}
 	}
 }
+#else
+static inline int setup_redirects(struct child_prog *prog, int squirrel[])
+{
+	return 0;
+}
+static inline void restore_redirects(int squirrel[])
+{
+}
+#endif
 
 static inline void cmdedit_set_initial_prompt(void)
 {
@@ -953,14 +972,18 @@ static int parse_command(char **command_ptr, struct job *job, int *inbg)
 {
 	char *command;
 	char *return_command = NULL;
-	char *src, *buf, *chptr;
+	char *src, *buf;
 	int argc_l = 0;
 	int done = 0;
 	int argv_alloced;
-	int i, saw_quote = 0;
+	int saw_quote = 0;
 	char quote = '\0';
 	int count;
 	struct child_prog *prog;
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
+	int i;
+	char *chptr;
+#endif
 
 	/* skip leading white space */
 	while (**command_ptr && isspace(**command_ptr))
@@ -988,9 +1011,11 @@ static int parse_command(char **command_ptr, struct job *job, int *inbg)
 
 	prog = job->progs;
 	prog->num_redirects = 0;
-	prog->redirects = NULL;
 	prog->is_stopped = 0;
 	prog->family = job;
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
+	prog->redirects = NULL;
+#endif
 
 	argv_alloced = 5;
 	prog->argv = xmalloc(sizeof(*prog->argv) * argv_alloced);
@@ -1046,6 +1071,7 @@ static int parse_command(char **command_ptr, struct job *job, int *inbg)
 					done = 1;
 				break;
 
+#ifdef CONFIG_LASH_PIPE_N_REDIRECTS
 			case '>':			/* redirects */
 			case '<':
 				i = prog->num_redirects++;
@@ -1143,6 +1169,7 @@ static int parse_command(char **command_ptr, struct job *job, int *inbg)
 				src--;			/* we'll ++ it at the end of the loop */
 
 				break;
+#endif
 
 			case '&':			/* background */
 				*inbg = 1;
@@ -1336,8 +1363,8 @@ static int run_command(struct job *newjob, int inbg, int outpipe[2])
 		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;
+					int squirrel[] = {-1, -1, -1};
 					setup_redirects(child, squirrel);
 					rcode = x->function(child);
 					restore_redirects(squirrel);