[PATCH v3 2/6] cmd: printf: import busybox-1.33.1 printf.c
Roland Gaudig
roland.gaudig-oss at weidmueller.com
Fri Jul 23 14:29:19 CEST 2021
From: Roland Gaudig <roland.gaudig at weidmueller.com>
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 at weidmueller.com>
---
(no changes since v1)
cmd/printf.c | 455 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 455 insertions(+)
create mode 100644 cmd/printf.c
diff --git a/cmd/printf.c b/cmd/printf.c
new file mode 100644
index 0000000000..a20fc33013
--- /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 at 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 */
+}
--
2.25.1
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