shell: consolidate builtin_foo.? into shell_common.?; delete obsolete shells

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 420 insertions, 0 deletions

diff --git a/shell/shell_common.c b/shell/shell_common.c
index 669a18d..3114ff3 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -33,3 +33,423 @@ int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
 
 	return *s == terminator;
 }
+
+/* read builtin */
+
+//TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL"
+//string. hush naturally has it, and ash has setvareq().
+//Here we can simply store "VAR=" at buffer start and store read data directly
+//after "=", then pass buffer to setvar() to consume.
+const char* FAST_FUNC
+shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val),
+	char       **argv,
+	const char *ifs,
+	int        read_flags,
+	const char *opt_n,
+	const char *opt_p,
+	const char *opt_t,
+	const char *opt_u
+)
+{
+	unsigned end_ms; /* -t TIMEOUT */
+	int fd; /* -u FD */
+	int nchars; /* -n NUM */
+	char **pp;
+	char *buffer;
+	struct termios tty, old_tty;
+	const char *retval;
+	int bufpos; /* need to be able to hold -1 */
+	int startword;
+	smallint backslash;
+
+	pp = argv;
+	while (*pp) {
+		if (!is_well_formed_var_name(*pp, '\0')) {
+			/* Mimic bash message */
+			bb_error_msg("read: '%s': not a valid identifier", *pp);
+			return (const char *)(uintptr_t)1;
+		}
+		pp++;
+	}
+
+	nchars = 0; /* if != 0, -n is in effect */
+	if (opt_n) {
+		nchars = bb_strtou(opt_n, NULL, 10);
+		if (nchars < 0 || errno)
+			return "invalid count";
+		/* note: "-n 0": off (bash 3.2 does this too) */
+	}
+	end_ms = 0;
+	if (opt_t) {
+		end_ms = bb_strtou(opt_t, NULL, 10);
+		if (errno || end_ms > UINT_MAX / 2048)
+			return "invalid timeout";
+		end_ms *= 1000;
+#if 0 /* even bash has no -t N.NNN support */
+		ts.tv_sec = bb_strtou(opt_t, &p, 10);
+		ts.tv_usec = 0;
+		/* EINVAL means number is ok, but not terminated by NUL */
+		if (*p == '.' && errno == EINVAL) {
+			char *p2;
+			if (*++p) {
+				int scale;
+				ts.tv_usec = bb_strtou(p, &p2, 10);
+				if (errno)
+					return "invalid timeout";
+				scale = p2 - p;
+				/* normalize to usec */
+				if (scale > 6)
+					return "invalid timeout";
+				while (scale++ < 6)
+					ts.tv_usec *= 10;
+			}
+		} else if (ts.tv_sec < 0 || errno) {
+			return "invalid timeout";
+		}
+		if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
+			return "invalid timeout";
+		}
+#endif /* if 0 */
+	}
+	fd = STDIN_FILENO;
+	if (opt_u) {
+		fd = bb_strtou(opt_u, NULL, 10);
+		if (fd < 0 || errno)
+			return "invalid file descriptor";
+	}
+
+	if (opt_p && isatty(fd)) {
+		fputs(opt_p, stderr);
+		fflush_all();
+	}
+
+	if (ifs == NULL)
+		ifs = defifs;
+
+	if (nchars || (read_flags & BUILTIN_READ_SILENT)) {
+		tcgetattr(fd, &tty);
+		old_tty = tty;
+		if (nchars) {
+			tty.c_lflag &= ~ICANON;
+			tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+		}
+		if (read_flags & BUILTIN_READ_SILENT) {
+			tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
+		}
+		/* This forces execution of "restoring" tcgetattr later */
+		read_flags |= BUILTIN_READ_SILENT;
+		/* if tcgetattr failed, tcsetattr will fail too.
+		 * Ignoring, it's harmless. */
+		tcsetattr(fd, TCSANOW, &tty);
+	}
+
+	retval = (const char *)(uintptr_t)0;
+	startword = 1;
+	backslash = 0;
+	if (end_ms) /* NB: end_ms stays nonzero: */
+		end_ms = ((unsigned)monotonic_ms() + end_ms) | 1;
+	buffer = NULL;
+	bufpos = 0;
+	do {
+		char c;
+
+		if (end_ms) {
+			int timeout;
+			struct pollfd pfd[1];
+
+			pfd[0].fd = fd;
+			pfd[0].events = POLLIN;
+			timeout = end_ms - (unsigned)monotonic_ms();
+			if (timeout <= 0 /* already late? */
+			 || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
+			) { /* timed out! */
+				retval = (const char *)(uintptr_t)1;
+				goto ret;
+			}
+		}
+
+		if ((bufpos & 0xff) == 0)
+			buffer = xrealloc(buffer, bufpos + 0x100);
+		if (nonblock_safe_read(fd, &buffer[bufpos], 1) != 1) {
+			retval = (const char *)(uintptr_t)1;
+			break;
+		}
+		c = buffer[bufpos];
+		if (c == '\0')
+			continue;
+		if (backslash) {
+			backslash = 0;
+			if (c != '\n')
+				goto put;
+			continue;
+		}
+		if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') {
+			backslash = 1;
+			continue;
+		}
+		if (c == '\n')
+			break;
+
+		/* $IFS splitting. NOT done if we run "read"
+		 * without variable names (bash compat).
+		 * Thus, "read" and "read REPLY" are not the same.
+		 */
+		if (argv[0]) {
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
+			const char *is_ifs = strchr(ifs, c);
+			if (startword && is_ifs) {
+				if (isspace(c))
+					continue;
+				/* it is a non-space ifs char */
+				startword--;
+				if (startword == 1) /* first one? */
+					continue; /* yes, it is not next word yet */
+			}
+			startword = 0;
+			if (argv[1] != NULL && is_ifs) {
+				buffer[bufpos] = '\0';
+				bufpos = 0;
+				setvar(*argv, buffer);
+				argv++;
+				/* can we skip one non-space ifs char? (2: yes) */
+				startword = isspace(c) ? 2 : 1;
+				continue;
+			}
+		}
+ put:
+		bufpos++;
+	} while (--nchars);
+
+	if (argv[0]) {
+		/* Remove trailing space $IFS chars */
+		while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL)
+			continue;
+		buffer[bufpos + 1] = '\0';
+		/* Use the remainder as a value for the next variable */
+		setvar(*argv, buffer);
+		/* Set the rest to "" */
+		while (*++argv)
+			setvar(*argv, "");
+	} else {
+		/* Note: no $IFS removal */
+		buffer[bufpos] = '\0';
+		setvar("REPLY", buffer);
+	}
+
+ ret:
+	free(buffer);
+	if (read_flags & BUILTIN_READ_SILENT)
+		tcsetattr(fd, TCSANOW, &old_tty);
+	return retval;
+}
+
+/* ulimit builtin */
+
+struct limits {
+	uint8_t cmd;            /* RLIMIT_xxx fit into it */
+	uint8_t factor_shift;   /* shift by to get rlim_{cur,max} values */
+	char option;
+	const char *name;
+};
+
+static const struct limits limits_tbl[] = {
+#ifdef RLIMIT_FSIZE
+	{ RLIMIT_FSIZE,		9,	'f',	"file size (blocks)" },
+#endif
+#ifdef RLIMIT_CPU
+	{ RLIMIT_CPU,		0,	't',	"cpu time (seconds)" },
+#endif
+#ifdef RLIMIT_DATA
+	{ RLIMIT_DATA,		10,	'd',	"data seg size (kb)" },
+#endif
+#ifdef RLIMIT_STACK
+	{ RLIMIT_STACK,		10,	's',	"stack size (kb)" },
+#endif
+#ifdef RLIMIT_CORE
+	{ RLIMIT_CORE,		9,	'c',	"core file size (blocks)" },
+#endif
+#ifdef RLIMIT_RSS
+	{ RLIMIT_RSS,		10,	'm',	"resident set size (kb)" },
+#endif
+#ifdef RLIMIT_MEMLOCK
+	{ RLIMIT_MEMLOCK,	10,	'l',	"locked memory (kb)" },
+#endif
+#ifdef RLIMIT_NPROC
+	{ RLIMIT_NPROC,		0,	'p',	"processes" },
+#endif
+#ifdef RLIMIT_NOFILE
+	{ RLIMIT_NOFILE,	0,	'n',	"file descriptors" },
+#endif
+#ifdef RLIMIT_AS
+	{ RLIMIT_AS,		10,	'v',	"address space (kb)" },
+#endif
+#ifdef RLIMIT_LOCKS
+	{ RLIMIT_LOCKS,		0,	'w',	"locks" },
+#endif
+};
+
+enum {
+	OPT_hard = (1 << 0),
+	OPT_soft = (1 << 1),
+};
+
+/* "-": treat args as parameters of option with ASCII code 1 */
+static const char ulimit_opt_string[] = "-HSa"
+#ifdef RLIMIT_FSIZE
+			"f::"
+#endif
+#ifdef RLIMIT_CPU
+			"t::"
+#endif
+#ifdef RLIMIT_DATA
+			"d::"
+#endif
+#ifdef RLIMIT_STACK
+			"s::"
+#endif
+#ifdef RLIMIT_CORE
+			"c::"
+#endif
+#ifdef RLIMIT_RSS
+			"m::"
+#endif
+#ifdef RLIMIT_MEMLOCK
+			"l::"
+#endif
+#ifdef RLIMIT_NPROC
+			"p::"
+#endif
+#ifdef RLIMIT_NOFILE
+			"n::"
+#endif
+#ifdef RLIMIT_AS
+			"v::"
+#endif
+#ifdef RLIMIT_LOCKS
+			"w::"
+#endif
+			;
+
+static void printlim(unsigned opts, const struct rlimit *limit,
+			const struct limits *l)
+{
+	rlim_t val;
+
+	val = limit->rlim_max;
+	if (!(opts & OPT_hard))
+		val = limit->rlim_cur;
+
+	if (val == RLIM_INFINITY)
+		printf("unlimited\n");
+	else {
+		val >>= l->factor_shift;
+		printf("%llu\n", (long long) val);
+	}
+}
+
+int FAST_FUNC
+shell_builtin_ulimit(char **argv)
+{
+	unsigned opts;
+	unsigned argc;
+
+	/* We can't use getopt32: need to handle commands like
+	 * ulimit 123 -c2 -l 456
+	 */
+
+	/* In case getopt was already called:
+	 * reset the libc getopt() function, which keeps internal state.
+	 */
+#ifdef __GLIBC__
+	optind = 0;
+#else /* BSD style */
+	optind = 1;
+	/* optreset = 1; */
+#endif
+	/* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
+
+        argc = 1;
+        while (argv[argc])
+                argc++;
+
+	opts = 0;
+	while (1) {
+		struct rlimit limit;
+		const struct limits *l;
+		int opt_char = getopt(argc, argv, ulimit_opt_string);
+
+		if (opt_char == -1)
+			break;
+		if (opt_char == 'H') {
+			opts |= OPT_hard;
+			continue;
+		}
+		if (opt_char == 'S') {
+			opts |= OPT_soft;
+			continue;
+		}
+
+		if (opt_char == 'a') {
+			for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
+				getrlimit(l->cmd, &limit);
+				printf("-%c: %-30s ", l->option, l->name);
+				printlim(opts, &limit, l);
+			}
+			continue;
+		}
+
+		if (opt_char == 1)
+			opt_char = 'f';
+		for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
+			if (opt_char == l->option) {
+				char *val_str;
+
+				getrlimit(l->cmd, &limit);
+
+				val_str = optarg;
+				if (!val_str && argv[optind] && argv[optind][0] != '-')
+					val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
+				if (val_str) {
+					rlim_t val;
+
+					if (strcmp(val_str, "unlimited") == 0)
+						val = RLIM_INFINITY;
+					else {
+						if (sizeof(val) == sizeof(int))
+							val = bb_strtou(val_str, NULL, 10);
+						else if (sizeof(val) == sizeof(long))
+							val = bb_strtoul(val_str, NULL, 10);
+						else
+							val = bb_strtoull(val_str, NULL, 10);
+						if (errno) {
+							bb_error_msg("bad number");
+							return EXIT_FAILURE;
+						}
+						val <<= l->factor_shift;
+					}
+//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
+					if (opts & OPT_hard)
+						limit.rlim_max = val;
+					if ((opts & OPT_soft) || opts == 0)
+						limit.rlim_cur = val;
+//bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
+					if (setrlimit(l->cmd, &limit) < 0) {
+						bb_perror_msg("error setting limit");
+						return EXIT_FAILURE;
+					}
+				} else {
+					printlim(opts, &limit, l);
+				}
+				break;
+			}
+		} /* for (every possible opt) */
+
+		if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) {
+			/* bad option. getopt already complained. */
+			break;
+		}
+
+	} /* while (there are options) */
+
+	return 0;
+}