cmd: printf: import busybox-1.33.1 printf.c

Import printf.c from the Busybox project, which provides Bash like
format string handling.

  src-url: https://git.busybox.net/busybox/
  commit bcc5b0e6caca6c7602a6a41f "Bump version to 1.33.1"
  version: 1.33.1

Signed-off-by: Roland Gaudig <roland.gaudig@weidmueller.com>

1 files changed, 455 insertions, 0 deletions

diff --git a/cmd/printf.c b/cmd/printf.c
new file mode 100644
index 0000000..a20fc33
--- /dev/null
+++ b/cmd/printf.c
@@ -0,0 +1,455 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * printf - format and print data
+ *
+ * Copyright 1999 Dave Cinege
+ * Portions copyright (C) 1990-1996 Free Software Foundation, Inc.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+/* Usage: printf format [argument...]
+ *
+ * A front end to the printf function that lets it be used from the shell.
+ *
+ * Backslash escapes:
+ *
+ * \" = double quote
+ * \\ = backslash
+ * \a = alert (bell)
+ * \b = backspace
+ * \c = produce no further output
+ * \f = form feed
+ * \n = new line
+ * \r = carriage return
+ * \t = horizontal tab
+ * \v = vertical tab
+ * \0ooo = octal number (ooo is 0 to 3 digits)
+ * \xhhh = hexadecimal number (hhh is 1 to 3 digits)
+ *
+ * Additional directive:
+ *
+ * %b = print an argument string, interpreting backslash escapes
+ *
+ * The 'format' argument is re-used as many times as necessary
+ * to convert all of the given arguments.
+ *
+ * David MacKenzie <djm@gnu.ai.mit.edu>
+ */
+/* 19990508 Busy Boxed! Dave Cinege */
+
+//config:config PRINTF
+//config:	bool "printf (3.8 kb)"
+//config:	default y
+//config:	help
+//config:	printf is used to format and print specified strings.
+//config:	It's similar to 'echo' except it has more options.
+
+//applet:IF_PRINTF(APPLET_NOFORK(printf, printf, BB_DIR_USR_BIN, BB_SUID_DROP, printf))
+
+//kbuild:lib-$(CONFIG_PRINTF) += printf.o
+//kbuild:lib-$(CONFIG_ASH_PRINTF)  += printf.o
+//kbuild:lib-$(CONFIG_HUSH_PRINTF) += printf.o
+
+//usage:#define printf_trivial_usage
+//usage:       "FORMAT [ARG]..."
+//usage:#define printf_full_usage "\n\n"
+//usage:       "Format and print ARG(s) according to FORMAT (a-la C printf)"
+//usage:
+//usage:#define printf_example_usage
+//usage:       "$ printf \"Val=%d\\n\" 5\n"
+//usage:       "Val=5\n"
+
+#include "libbb.h"
+
+/* A note on bad input: neither bash 3.2 nor coreutils 6.10 stop on it.
+ * They report it:
+ *  bash: printf: XXX: invalid number
+ *  printf: XXX: expected a numeric value
+ *  bash: printf: 123XXX: invalid number
+ *  printf: 123XXX: value not completely converted
+ * but then they use 0 (or partially converted numeric prefix) as a value
+ * and continue. They exit with 1 in this case.
+ * Both accept insane field width/precision (e.g. %9999999999.9999999999d).
+ * Both print error message and assume 0 if %*.*f width/precision is "bad"
+ *  (but negative numbers are not "bad").
+ * Both accept negative numbers for %u specifier.
+ *
+ * We try to be compatible.
+ */
+
+typedef void FAST_FUNC (*converter)(const char *arg, void *result);
+
+static int multiconvert(const char *arg, void *result, converter convert)
+{
+	if (*arg == '"' || *arg == '\'') {
+		arg = utoa((unsigned char)arg[1]);
+	}
+	errno = 0;
+	convert(arg, result);
+	if (errno) {
+		bb_error_msg("invalid number '%s'", arg);
+		return 1;
+	}
+	return 0;
+}
+
+static void FAST_FUNC conv_strtoull(const char *arg, void *result)
+{
+	/* Allow leading '+' - bb_strtoull() by itself does not allow it,
+	 * and probably shouldn't (other callers might require purely numeric
+	 * inputs to be allowed.
+	 */
+	if (arg[0] == '+')
+		arg++;
+	*(unsigned long long*)result = bb_strtoull(arg, NULL, 0);
+	/* both coreutils 6.10 and bash 3.2:
+	 * $ printf '%x\n' -2
+	 * fffffffffffffffe
+	 * Mimic that:
+	 */
+	if (errno) {
+		*(unsigned long long*)result = bb_strtoll(arg, NULL, 0);
+	}
+}
+static void FAST_FUNC conv_strtoll(const char *arg, void *result)
+{
+	if (arg[0] == '+')
+		arg++;
+	*(long long*)result = bb_strtoll(arg, NULL, 0);
+}
+static void FAST_FUNC conv_strtod(const char *arg, void *result)
+{
+	char *end;
+	/* Well, this one allows leading whitespace... so what? */
+	/* What I like much less is that "-" accepted too! :( */
+	*(double*)result = strtod(arg, &end);
+	if (end[0]) {
+		errno = ERANGE;
+		*(double*)result = 0;
+	}
+}
+
+/* Callers should check errno to detect errors */
+static unsigned long long my_xstrtoull(const char *arg)
+{
+	unsigned long long result;
+	if (multiconvert(arg, &result, conv_strtoull))
+		result = 0;
+	return result;
+}
+static long long my_xstrtoll(const char *arg)
+{
+	long long result;
+	if (multiconvert(arg, &result, conv_strtoll))
+		result = 0;
+	return result;
+}
+static double my_xstrtod(const char *arg)
+{
+	double result;
+	multiconvert(arg, &result, conv_strtod);
+	return result;
+}
+
+/* Handles %b; return 1 if output is to be short-circuited by \c */
+static int print_esc_string(const char *str)
+{
+	char c;
+	while ((c = *str) != '\0') {
+		str++;
+		if (c == '\\') {
+			/* %b also accepts 4-digit octals of the form \0### */
+			if (*str == '0') {
+				if ((unsigned char)(str[1] - '0') < 8) {
+					/* 2nd char is 0..7: skip leading '0' */
+					str++;
+				}
+			}
+			else if (*str == 'c') {
+				return 1;
+			}
+			{
+				/* optimization: don't force arg to be on-stack,
+				 * use another variable for that. */
+				const char *z = str;
+				c = bb_process_escape_sequence(&z);
+				str = z;
+			}
+		}
+		putchar(c);
+	}
+
+	return 0;
+}
+
+static void print_direc(char *format, unsigned fmt_length,
+		int field_width, int precision,
+		const char *argument)
+{
+	long long llv;
+	double dv;
+	char saved;
+	char *have_prec, *have_width;
+
+	saved = format[fmt_length];
+	format[fmt_length] = '\0';
+
+	have_prec = strstr(format, ".*");
+	have_width = strchr(format, '*');
+	if (have_width - 1 == have_prec)
+		have_width = NULL;
+
+	/* multiconvert sets errno = 0, but %s needs it cleared */
+	errno = 0;
+
+	switch (format[fmt_length - 1]) {
+	case 'c':
+		printf(format, *argument);
+		break;
+	case 'd':
+	case 'i':
+		llv = my_xstrtoll(skip_whitespace(argument));
+ print_long:
+		if (!have_width) {
+			if (!have_prec)
+				printf(format, llv);
+			else
+				printf(format, precision, llv);
+		} else {
+			if (!have_prec)
+				printf(format, field_width, llv);
+			else
+				printf(format, field_width, precision, llv);
+		}
+		break;
+	case 'o':
+	case 'u':
+	case 'x':
+	case 'X':
+		llv = my_xstrtoull(skip_whitespace(argument));
+		/* cheat: unsigned long and long have same width, so... */
+		goto print_long;
+	case 's':
+		/* Are char* and long long the same? */
+		if (sizeof(argument) == sizeof(llv)) {
+			llv = (long long)(ptrdiff_t)argument;
+			goto print_long;
+		} else {
+			/* Hope compiler will optimize it out by moving call
+			 * instruction after the ifs... */
+			if (!have_width) {
+				if (!have_prec)
+					printf(format, argument, /*unused:*/ argument, argument);
+				else
+					printf(format, precision, argument, /*unused:*/ argument);
+			} else {
+				if (!have_prec)
+					printf(format, field_width, argument, /*unused:*/ argument);
+				else
+					printf(format, field_width, precision, argument);
+			}
+			break;
+		}
+	case 'f':
+	case 'e':
+	case 'E':
+	case 'g':
+	case 'G':
+		dv = my_xstrtod(argument);
+		if (!have_width) {
+			if (!have_prec)
+				printf(format, dv);
+			else
+				printf(format, precision, dv);
+		} else {
+			if (!have_prec)
+				printf(format, field_width, dv);
+			else
+				printf(format, field_width, precision, dv);
+		}
+		break;
+	} /* switch */
+
+	format[fmt_length] = saved;
+}
+
+/* Handle params for "%*.*f". Negative numbers are ok (compat). */
+static int get_width_prec(const char *str)
+{
+	int v = bb_strtoi(str, NULL, 10);
+	if (errno) {
+		bb_error_msg("invalid number '%s'", str);
+		v = 0;
+	}
+	return v;
+}
+
+/* Print the text in FORMAT, using ARGV for arguments to any '%' directives.
+   Return advanced ARGV.  */
+static char **print_formatted(char *f, char **argv, int *conv_err)
+{
+	char *direc_start;      /* Start of % directive.  */
+	unsigned direc_length;  /* Length of % directive.  */
+	int field_width;        /* Arg to first '*' */
+	int precision;          /* Arg to second '*' */
+	char **saved_argv = argv;
+
+	for (; *f; ++f) {
+		switch (*f) {
+		case '%':
+			direc_start = f++;
+			direc_length = 1;
+			field_width = precision = 0;
+			if (*f == '%') {
+				bb_putchar('%');
+				break;
+			}
+			if (*f == 'b') {
+				if (*argv) {
+					if (print_esc_string(*argv))
+						return saved_argv; /* causes main() to exit */
+					++argv;
+				}
+				break;
+			}
+			if (*f && strchr("-+ #", *f)) {
+				++f;
+				++direc_length;
+			}
+			if (*f == '*') {
+				++f;
+				++direc_length;
+				if (*argv)
+					field_width = get_width_prec(*argv++);
+			} else {
+				while (isdigit(*f)) {
+					++f;
+					++direc_length;
+				}
+			}
+			if (*f == '.') {
+				++f;
+				++direc_length;
+				if (*f == '*') {
+					++f;
+					++direc_length;
+					if (*argv)
+						precision = get_width_prec(*argv++);
+				} else {
+					while (isdigit(*f)) {
+						++f;
+						++direc_length;
+					}
+				}
+			}
+
+			/* Remove "lLhz" size modifiers, repeatedly.
+			 * bash does not like "%lld", but coreutils
+			 * happily takes even "%Llllhhzhhzd"!
+			 * We are permissive like coreutils */
+			while ((*f | 0x20) == 'l' || *f == 'h' || *f == 'z') {
+				overlapping_strcpy(f, f + 1);
+			}
+			/* Add "ll" if integer modifier, then print */
+			{
+				static const char format_chars[] ALIGN1 = "diouxXfeEgGcs";
+				char *p = strchr(format_chars, *f);
+				/* needed - try "printf %" without it */
+				if (p == NULL || *f == '\0') {
+					bb_error_msg("%s: invalid format", direc_start);
+					/* causes main() to exit with error */
+					return saved_argv - 1;
+				}
+				++direc_length;
+				if (p - format_chars <= 5) {
+					/* it is one of "diouxX" */
+					p = xmalloc(direc_length + 3);
+					memcpy(p, direc_start, direc_length);
+					p[direc_length + 1] = p[direc_length - 1];
+					p[direc_length - 1] = 'l';
+					p[direc_length] = 'l';
+					//bb_error_msg("<%s>", p);
+					direc_length += 2;
+					direc_start = p;
+				} else {
+					p = NULL;
+				}
+				if (*argv) {
+					print_direc(direc_start, direc_length, field_width,
+								precision, *argv++);
+				} else {
+					print_direc(direc_start, direc_length, field_width,
+								precision, "");
+				}
+				*conv_err |= errno;
+				free(p);
+			}
+			break;
+		case '\\':
+			if (*++f == 'c') {
+				return saved_argv; /* causes main() to exit */
+			}
+			bb_putchar(bb_process_escape_sequence((const char **)&f));
+			f--;
+			break;
+		default:
+			putchar(*f);
+		}
+	}
+
+	return argv;
+}
+
+int printf_main(int argc UNUSED_PARAM, char **argv)
+{
+	int conv_err;
+	char *format;
+	char **argv2;
+
+	/* We must check that stdout is not closed.
+	 * The reason for this is highly non-obvious.
+	 * printf_main is used from shell.
+	 * Shell must correctly handle 'printf "%s" foo'
+	 * if stdout is closed. With stdio, output gets shoveled into
+	 * stdout buffer, and even fflush cannot clear it out. It seems that
+	 * even if libc receives EBADF on write attempts, it feels determined
+	 * to output data no matter what. So it will try later,
+	 * and possibly will clobber future output. Not good. */
+// TODO: check fcntl() & O_ACCMODE == O_WRONLY or O_RDWR?
+	if (fcntl(1, F_GETFL) == -1)
+		return 1; /* match coreutils 6.10 (sans error msg to stderr) */
+	//if (dup2(1, 1) != 1) - old way
+	//	return 1;
+
+	/* bash builtin errors out on "printf '-%s-\n' foo",
+	 * coreutils-6.9 works. Both work with "printf -- '-%s-\n' foo".
+	 * We will mimic coreutils. */
+	if (argv[1] && argv[1][0] == '-' && argv[1][1] == '-' && !argv[1][2])
+		argv++;
+	if (!argv[1]) {
+		if (ENABLE_ASH_PRINTF
+		 && applet_name[0] != 'p'
+		) {
+			bb_simple_error_msg("usage: printf FORMAT [ARGUMENT...]");
+			return 2; /* bash compat */
+		}
+		bb_show_usage();
+	}
+
+	format = argv[1];
+	argv2 = argv + 2;
+
+	conv_err = 0;
+	do {
+		argv = argv2;
+		argv2 = print_formatted(format, argv, &conv_err);
+	} while (argv2 > argv && *argv2);
+
+	/* coreutils compat (bash doesn't do this):
+	if (*argv)
+		fprintf(stderr, "excess args ignored");
+	*/
+
+	return (argv2 < argv) /* if true, print_formatted errored out */
+		|| conv_err; /* print_formatted saw invalid number */
+}