shell: split read builtin from ash

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

TODO_config_nommu

@@ -859,8 +859,6 @@ CONFIG_FEATURE_SH_IS_HUSH=y
 # CONFIG_ASH is not set
 # CONFIG_ASH_BASH_COMPAT is not set
 # CONFIG_ASH_JOB_CONTROL is not set
-# CONFIG_ASH_READ_NCHARS is not set
-# CONFIG_ASH_READ_TIMEOUT is not set
 # CONFIG_ASH_ALIAS is not set
 # CONFIG_ASH_GETOPTS is not set
 # CONFIG_ASH_BUILTIN_ECHO is not set

scripts/defconfig

@@ -856,8 +856,6 @@ CONFIG_FEATURE_SH_IS_ASH=y
 CONFIG_ASH=y
 CONFIG_ASH_BASH_COMPAT=y
 CONFIG_ASH_JOB_CONTROL=y
-CONFIG_ASH_READ_NCHARS=y
-CONFIG_ASH_READ_TIMEOUT=y
 CONFIG_ASH_ALIAS=y
 CONFIG_ASH_GETOPTS=y
 CONFIG_ASH_BUILTIN_ECHO=y

shell/Kbuild

@@ -5,7 +5,7 @@
 # Licensed under the GPL v2, see the file LICENSE in this tarball.
 
 lib-y:=
-lib-$(CONFIG_ASH)      += ash.o ash_ptr_hack.o
+lib-$(CONFIG_ASH)      += ash.o ash_ptr_hack.o shell_common.o builtin_read.o
 lib-$(CONFIG_HUSH)     += hush.o match.o
 lib-$(CONFIG_CTTYHACK) += cttyhack.o
 

shell/ash.c

@@ -2,18 +2,18 @@
 /*
  * ash shell port for busybox
  *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Original BSD copyright notice is retained at the end of this file.
+ *
  * Copyright (c) 1989, 1991, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.
  *
  * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
  * was re-ported from NetBSD and debianized.
  *
- * This code is derived from software contributed to Berkeley by
- * Kenneth Almquist.
- *
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
- *
- * Original BSD copyright notice is retained at the end of this file.
  */
 
 /*
@@ -34,8 +34,6 @@
 
 #define PROFILE 0
 
-#define IFS_BROKEN
-
 #define JOBS ENABLE_ASH_JOB_CONTROL
 
 #if DEBUG
@@ -50,6 +48,9 @@
 #include <paths.h>
 #include <setjmp.h>
 #include <fnmatch.h>
+
+#include "shell_common.h"
+#include "builtin_read.h"
 #include "math.h"
 #if ENABLE_ASH_RANDOM_SUPPORT
 # include "random.h"
@@ -1737,13 +1738,6 @@ struct localvar {
 # define VDYNAMIC       0
 #endif
 
-#ifdef IFS_BROKEN
-static const char defifsvar[] ALIGN1 = "IFS= \t\n";
-#define defifs (defifsvar + 4)
-#else
-static const char defifs[] ALIGN1 = " \t\n";
-#endif
-
 
 /* Need to be before varinit_data[] */
 #if ENABLE_LOCALE_SUPPORT
@@ -1774,7 +1768,7 @@ static const struct {
 	const char *text;
 	void (*func)(const char *) FAST_FUNC;
 } varinit_data[] = {
-#ifdef IFS_BROKEN
+#if IFS_BROKEN
 	{ VSTRFIXED|VTEXTFIXED       , defifsvar   , NULL            },
 #else
 	{ VSTRFIXED|VTEXTFIXED|VUNSET, "IFS\0"     , NULL            },
@@ -12499,211 +12493,53 @@ typedef enum __rlimit_resource rlim_t;
 static int FAST_FUNC
 readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
-	static const char *const arg_REPLY[] = { "REPLY", NULL };
+	char *opt_n = NULL;
-
+	char *opt_p = NULL;
-	char **ap;
+	char *opt_t = NULL;
-	int backslash;
+	char *opt_u = NULL;
-	char c;
+	int read_flags = 0;
-	int rflag;
+	const char *r;
-	char *prompt;
-	const char *ifs;
-	char *p;
-	int startword;
-	int status;
 	int i;
-	int fd = 0;
-#if ENABLE_ASH_READ_NCHARS
-	int nchars = 0; /* if != 0, -n is in effect */
-	int silent = 0;
-	struct termios tty, old_tty;
-#endif
-#if ENABLE_ASH_READ_TIMEOUT
-	unsigned end_ms = 0;
-	unsigned timeout = 0;
-#endif
 
-	rflag = 0;
+	while ((i = nextopt("p:u:rt:n:s")) != '\0') {
-	prompt = NULL;
-	while ((i = nextopt("p:u:r"
-		IF_ASH_READ_TIMEOUT("t:")
-		IF_ASH_READ_NCHARS("n:s")
-	)) != '\0') {
 		switch (i) {
 		case 'p':
-			prompt = optionarg;
+			opt_p = optionarg;
 			break;
-#if ENABLE_ASH_READ_NCHARS
 		case 'n':
-			nchars = bb_strtou(optionarg, NULL, 10);
+			opt_n = optionarg;
-			if (nchars < 0 || errno)
-				ash_msg_and_raise_error("invalid count");
-			/* nchars == 0: off (bash 3.2 does this too) */
 			break;
 		case 's':
-			silent = 1;
+			read_flags |= BUILTIN_READ_SILENT;
 			break;
-#endif
-#if ENABLE_ASH_READ_TIMEOUT
 		case 't':
-			timeout = bb_strtou(optionarg, NULL, 10);
+			opt_t = optionarg;
-			if (errno || timeout > UINT_MAX / 2048)
-				ash_msg_and_raise_error("invalid timeout");
-			timeout *= 1000;
-#if 0 /* even bash have no -t N.NNN support */
-			ts.tv_sec = bb_strtou(optionarg, &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)
-						ash_msg_and_raise_error("invalid timeout");
-					scale = p2 - p;
-					/* normalize to usec */
-					if (scale > 6)
-						ash_msg_and_raise_error("invalid timeout");
-					while (scale++ < 6)
-						ts.tv_usec *= 10;
-				}
-			} else if (ts.tv_sec < 0 || errno) {
-				ash_msg_and_raise_error("invalid timeout");
-			}
-			if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
-				ash_msg_and_raise_error("invalid timeout");
-			}
-#endif /* if 0 */
 			break;
-#endif
 		case 'r':
-			rflag = 1;
+			read_flags |= BUILTIN_READ_RAW;
 			break;
 		case 'u':
-			fd = bb_strtou(optionarg, NULL, 10);
+			opt_u = optionarg;
-			if (fd < 0 || errno)
-				ash_msg_and_raise_error("invalid file descriptor");
 			break;
 		default:
 			break;
 		}
 	}
-	if (prompt && isatty(fd)) {
-		out2str(prompt);
-	}
-	ap = argptr;
-	if (*ap == NULL)
-		ap = (char**)arg_REPLY;
-	ifs = bltinlookup("IFS");
-	if (ifs == NULL)
-		ifs = defifs;
-#if ENABLE_ASH_READ_NCHARS
-	tcgetattr(fd, &tty);
-	old_tty = tty;
-	if (nchars || silent) {
-		if (nchars) {
-			tty.c_lflag &= ~ICANON;
-			tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
-		}
-		if (silent) {
-			tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
-		}
-		/* if tcgetattr failed, tcsetattr will fail too.
-		 * Ignoring, it's harmless. */
-		tcsetattr(fd, TCSANOW, &tty);
-	}
-#endif
 
-	status = 0;
+	r = builtin_read(setvar,
-	startword = 1;
+		argptr,
-	backslash = 0;
+		bltinlookup("IFS"), /* can be NULL */
-#if ENABLE_ASH_READ_TIMEOUT
+		read_flags,
-	if (timeout) /* NB: ensuring end_ms is nonzero */
+		opt_n,
-		end_ms = ((unsigned)monotonic_ms() + timeout) | 1;
+		opt_p,
-#endif
+		opt_t,
-	STARTSTACKSTR(p);
+		opt_u
-	do {
+	);
-		const char *is_ifs;
 
-#if ENABLE_ASH_READ_TIMEOUT
+	if ((uintptr_t)r > 1)
-		if (end_ms) {
+		ash_msg_and_raise_error(r);
-			struct pollfd pfd[1];
-			pfd[0].fd = fd;
-			pfd[0].events = POLLIN;
-			timeout = end_ms - (unsigned)monotonic_ms();
-			if ((int)timeout <= 0 /* already late? */
-			 || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
-			) { /* timed out! */
-#if ENABLE_ASH_READ_NCHARS
-				tcsetattr(fd, TCSANOW, &old_tty);
-#endif
-				return 1;
-			}
-		}
-#endif
-		if (nonblock_safe_read(fd, &c, 1) != 1) {
-			status = 1;
-			break;
-		}
-		if (c == '\0')
-			continue;
-		if (backslash) {
-			backslash = 0;
-			if (c != '\n')
-				goto put;
-			continue;
-		}
-		if (!rflag && c == '\\') {
-			backslash = 1;
-			continue;
-		}
-		if (c == '\n')
-			break;
-		/* $IFS splitting */
-/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
-		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 (ap[1] != NULL && is_ifs) {
-			const char *beg;
-			STACKSTRNUL(p);
-			beg = stackblock();
-			setvar(*ap, beg, 0);
-			ap++;
-			/* can we skip one non-space ifs char? (2: yes) */
-			startword = isspace(c) ? 2 : 1;
-			STARTSTACKSTR(p);
-			continue;
-		}
- put:
-		STPUTC(c, p);
-	}
-/* end of do {} while: */
-#if ENABLE_ASH_READ_NCHARS
-	while (--nchars);
-#else
-	while (1);
-#endif
 
-#if ENABLE_ASH_READ_NCHARS
+	return (uintptr_t)r;
-	tcsetattr(fd, TCSANOW, &old_tty);
-#endif
-
-	STACKSTRNUL(p);
-	/* Remove trailing space ifs chars */
-	while ((char *)stackblock() <= --p && isspace(*p) && strchr(ifs, *p) != NULL)
-		*p = '\0';
-	setvar(*ap, stackblock(), 0);
-	while (*++ap != NULL)
-		setvar(*ap, nullstr, 0);
-	return status;
 }
 
 static int FAST_FUNC

shell/ash_test/ash-read/read_REPLY.right

@@ -0,0 +1,5 @@
+test 1: |  abc1  def  |
+test 2: |  \abc2  d\ef  |
+test 3: |abc3  def|
+test 4: |\abc4  d\ef|
+Done

shell/ash_test/ash-read/read_REPLY.tests

@@ -0,0 +1,5 @@
+echo '  \abc1  d\ef  ' | ( read         ; echo "test 1: |$REPLY|" )
+echo '  \abc2  d\ef  ' | ( read -r      ; echo "test 2: |$REPLY|" )
+echo '  \abc3  d\ef  ' | ( read    REPLY; echo "test 3: |$REPLY|" )
+echo '  \abc4  d\ef  ' | ( read -r REPLY; echo "test 4: |$REPLY|" )
+echo Done

shell/builtin_read.c

@@ -0,0 +1,205 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Adapted from ash applet code
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * Copyright (c) 2010 Denys Vlasenko
+ * Split from ash.c
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+#include "libbb.h"
+#include "shell_common.h"
+#include "builtin_read.h"
+
+const char* FAST_FUNC
+builtin_read(void (*setvar)(const char *name, const char *val, int flags),
+	char       **argv,
+	const char *ifs,
+	int        read_flags,
+	const char *opt_n,
+	const char *opt_p,
+	const char *opt_t,
+	const char *opt_u
+)
+{
+	static const char *const arg_REPLY[] = { "REPLY", NULL };
+
+	unsigned end_ms; /* -t TIMEOUT */
+	int fd; /* -u FD */
+	int nchars; /* -n NUM */
+	char *buffer;
+	struct termios tty, old_tty;
+	const char *retval;
+	int bufpos; /* need to be able to hold -1 */
+	int startword;
+	smallint backslash;
+
+	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 (argv[0] == NULL)
+		argv = (char**)arg_REPLY;
+	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;
+		const char *is_ifs;
+
+		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 */
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
+		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, 0);
+			argv++;
+			/* can we skip one non-space ifs char? (2: yes) */
+			startword = isspace(c) ? 2 : 1;
+			continue;
+		}
+ put:
+		bufpos++;
+	} while (--nchars);
+
+	/* Remove trailing space ifs chars */
+	while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL)
+		continue;
+	buffer[bufpos + 1] = '\0';
+
+	setvar(*argv, buffer, 0);
+
+	while (*++argv != NULL)
+		setvar(*argv, "", 0);
+ ret:
+	free(buffer);
+	if (read_flags & BUILTIN_READ_SILENT)
+		tcsetattr(fd, TCSANOW, &old_tty);
+	return retval;
+}

shell/builtin_read.h

@@ -0,0 +1,42 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Adapted from ash applet code
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * Copyright (c) 2010 Denys Vlasenko
+ * Split from ash.c
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+#ifndef SHELL_BUILTIN_READ_H
+#define SHELL_BUILTIN_READ_H 1
+
+PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
+
+enum {
+	BUILTIN_READ_SILENT = 1 << 0,
+	BUILTIN_READ_RAW    = 1 << 1,
+};
+
+const char* FAST_FUNC
+builtin_read(void (*setvar)(const char *name, const char *val, int flags),
+	char       **argv,
+	const char *ifs,
+	int        read_flags,
+	const char *opt_n,
+	const char *opt_p,
+	const char *opt_t,
+	const char *opt_u
+);
+
+POP_SAVED_FUNCTION_VISIBILITY
+
+#endif

shell/match.c

@@ -1,16 +1,16 @@
 /*
  * ##/%% variable matching code ripped out of ash shell for code sharing
  *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ *
  * Copyright (c) 1989, 1991, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.
  *
  * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
  * was re-ported from NetBSD and debianized.
- *
- * This code is derived from software contributed to Berkeley by
- * Kenneth Almquist.
- *
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 #ifdef STANDALONE
 # include <stdbool.h>

shell/match.h

@@ -1,5 +1,8 @@
 /* match.h - interface to shell ##/%% matching code */
 
+#ifndef SHELL_MATCH_H
+#define SHELL_MATCH_H 1
+
 PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
 typedef char *(*scan_t)(char *string, char *match, bool match_at_left);
@@ -24,3 +27,5 @@ static inline scan_t pick_scan(char op1, char op2, bool *match_at_left)
 }
 
 POP_SAVED_FUNCTION_VISIBILITY
+
+#endif

shell/math.c

@@ -1,20 +1,17 @@
 /*
  * arithmetic code ripped out of ash shell for code sharing
  *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Original BSD copyright notice is retained at the end of this file.
+ *
  * Copyright (c) 1989, 1991, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.
  *
  * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
  * was re-ported from NetBSD and debianized.
  *
- * This code is derived from software contributed to Berkeley by
- * Kenneth Almquist.
- *
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
- *
- * Original BSD copyright notice is retained at the end of this file.
- */
-/*
  * rewrite arith.y to micro stack based cryptic algorithm by
  * Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>
  *
@@ -25,6 +22,8 @@
  * used in busybox and size optimizations,
  * rewrote arith (see notes to this), added locale support,
  * rewrote dynamic variables.
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 #include "libbb.h"
 #include "math.h"

shell/random.h

@@ -6,6 +6,10 @@
  *
  * Licensed under GPLv2, see file LICENSE in this tarball for details.
  */
+#ifndef SHELL_RANDOM_H
+#define SHELL_RANDOM_H 1
+
+PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
 typedef struct random_t {
 	/* Random number generators */
@@ -23,3 +27,7 @@ typedef struct random_t {
 	((rnd)->galois_LFSR = 0)
 
 uint32_t next_random(random_t *rnd) FAST_FUNC;
+
+POP_SAVED_FUNCTION_VISIBILITY
+
+#endif

shell/shell_common.c

@@ -0,0 +1,26 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Adapted from ash applet code
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * Copyright (c) 2010 Denys Vlasenko
+ * Split from ash.c
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+#include "libbb.h"
+#include "shell_common.h"
+
+#if IFS_BROKEN
+const char defifsvar[] ALIGN1 = "IFS= \t\n";
+#else
+const char defifs[] ALIGN1 = " \t\n";
+#endif

shell/shell_common.h

@@ -0,0 +1,35 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Adapted from ash applet code
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * Copyright (c) 2010 Denys Vlasenko
+ * Split from ash.c
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+#ifndef SHELL_COMMON_H
+#define SHELL_COMMON_H 1
+
+PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
+
+#define IFS_BROKEN 1
+
+#if IFS_BROKEN
+extern const char defifsvar[]; /* "IFS= \t\n" */
+#define defifs (defifsvar + 4)
+#else
+extern const char defifs[]; /* " \t\n" */
+#endif
+
+POP_SAVED_FUNCTION_VISIBILITY
+
+#endif