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Sourcecode: coreutils version File versions

printf.c

/* printf - format and print data
   Copyright (C) 1990-2004 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* 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
   \ooo = octal number (ooo is 1 to 3 digits)
   \xhh = hexadecimal number (hhh is 1 to 2 digits)
   \uhhhh = 16-bit Unicode character (hhhh is 4 digits)
   \Uhhhhhhhh = 32-bit Unicode character (hhhhhhhh is 8 digits)

   Additional directive:

   %b = print an argument string, interpreting backslash escapes,
     except that octal escapes are of the form \0 or \0ooo.

   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> */

#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#include <getopt.h>

#include "system.h"
#include "c-strtod.h"
#include "long-options.h"
#include "error.h"
#include "unicodeio.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "printf"

#define AUTHORS "David MacKenzie"

#define isodigit(c) ((c) >= '0' && (c) <= '7')
#define hextobin(c) ((c) >= 'a' && (c) <= 'f' ? (c) - 'a' + 10 : \
                 (c) >= 'A' && (c) <= 'F' ? (c) - 'A' + 10 : (c) - '0')
#define octtobin(c) ((c) - '0')

/* A value for field_width or precision that indicates it was not specified.  */
#define UNSPECIFIED INT_MIN

/* The value to return to the calling program.  */
static int exit_status;

/* Non-zero if the POSIXLY_CORRECT environment variable is set.  */
static int posixly_correct;

/* This message appears in N_() here rather than just in _() below because
   the sole use would have been in a #define.  */
static char *const cfcc_msg =
 N_("warning: %s: character(s) following character constant have been ignored");

/* The name this program was run with. */
char *program_name;

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
           program_name);
  else
    {
      printf (_("\
Usage: %s FORMAT [ARGUMENT]...\n\
  or:  %s OPTION\n\
"),
            program_name, program_name);
      fputs (_("\
Print ARGUMENT(s) according to FORMAT.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
FORMAT controls the output as in C printf.  Interpreted sequences are:\n\
\n\
  \\\"      double quote\n\
  \\NNN    character with octal value NNN (1 to 3 digits)\n\
  \\\\      backslash\n\
"), stdout);
      fputs (_("\
  \\a      alert (BEL)\n\
  \\b      backspace\n\
  \\c      produce no further output\n\
  \\f      form feed\n\
"), stdout);
      fputs (_("\
  \\n      new line\n\
  \\r      carriage return\n\
  \\t      horizontal tab\n\
  \\v      vertical tab\n\
"), stdout);
      fputs (_("\
  \\xNN    byte with hexadecimal value NN (1 to 2 digits)\n\
\n\
  \\uNNNN  character with hexadecimal value NNNN (4 digits)\n\
  \\UNNNNNNNN  character with hexadecimal value NNNNNNNN (8 digits)\n\
"), stdout);
      fputs (_("\
  %%      a single %\n\
  %b      ARGUMENT as a string with `\\' escapes interpreted,\n\
            except that octal escapes are of the form \\0 or \\0NNN\n\
\n\
and all C format specifications ending with one of diouxXfeEgGcs, with\n\
ARGUMENTs converted to proper type first.  Variable widths are handled.\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}

static void
verify (const char *s, const char *end)
{
  if (errno)
    {
      error (0, errno, "%s", s);
      exit_status = 1;
    }
  else if (*end)
    {
      if (s == end)
      error (0, 0, _("%s: expected a numeric value"), s);
      else
      error (0, 0, _("%s: value not completely converted"), s);
      exit_status = 1;
    }
}

#define STRTOX(TYPE, FUNC_NAME, LIB_FUNC_EXPR)                     \
static TYPE                                            \
FUNC_NAME (s)                                                \
     const char *s;                                          \
{                                                      \
  char *end;                                                 \
  TYPE val;                                            \
                                                       \
  if (*s == '\"' || *s == '\'')                                    \
    {                                                  \
      val = *(unsigned char *) ++s;                          \
      /* If POSIXLY_CORRECT is not set, then give a warning that there   \
       are characters following the character constant and that GNU      \
       printf is ignoring those characters.  If POSIXLY_CORRECT *is*     \
       set, then don't give the warning.  */                       \
      if (*++s != 0 && !posixly_correct)                     \
      error (0, 0, _(cfcc_msg), s);                          \
    }                                                  \
  else                                                       \
    {                                                  \
      errno = 0;                                       \
      val = LIB_FUNC_EXPR;                                   \
      verify (s, end);                                       \
    }                                                  \
  return val;                                                \
}                                                      \

STRTOX (unsigned long int, xstrtoul, (strtoul (s, &end, 0)))
STRTOX (long int,          xstrtol,  (strtol  (s, &end, 0)))
STRTOX (double,            xstrtod,  (c_strtod (s, &end)))

/* Output a single-character \ escape.  */

static void
print_esc_char (int c)
{
  switch (c)
    {
    case 'a':                 /* Alert. */
      putchar (7);
      break;
    case 'b':                 /* Backspace. */
      putchar (8);
      break;
    case 'c':                 /* Cancel the rest of the output. */
      exit (EXIT_SUCCESS);
      break;
    case 'f':                 /* Form feed. */
      putchar (12);
      break;
    case 'n':                 /* New line. */
      putchar (10);
      break;
    case 'r':                 /* Carriage return. */
      putchar (13);
      break;
    case 't':                 /* Horizontal tab. */
      putchar (9);
      break;
    case 'v':                 /* Vertical tab. */
      putchar (11);
      break;
    default:
      putchar (c);
      break;
    }
}

/* Print a \ escape sequence starting at ESCSTART.
   Return the number of characters in the escape sequence
   besides the backslash.
   If OCTAL_0 is nonzero, octal escapes are of the form \0ooo, where o
   is an octal digit; otherwise they are of the form \ooo.  */

static int
print_esc (const char *escstart, bool octal_0)
{
  register const char *p = escstart + 1;
  int esc_value = 0;          /* Value of \nnn escape. */
  int esc_length;       /* Length of \nnn escape. */

  if (!posixly_correct && *p == 'x')
    {
      /* A hexadecimal \xhh escape sequence must have 1 or 2 hex. digits.  */
      for (esc_length = 0, ++p;
         esc_length < 2 && ISXDIGIT (*p);
         ++esc_length, ++p)
      esc_value = esc_value * 16 + hextobin (*p);
      if (esc_length == 0)
      error (EXIT_FAILURE, 0, _("missing hexadecimal number in escape"));
      putchar (esc_value);
    }
  else if (isodigit (*p))
    {
      /* Parse \0ooo (if octal_0 && *p == '0') or \ooo (otherwise).
         Allow \ooo if octal_0 && *p != '0'; this is an undocumented
         extension to POSIX that is compatible with Bash 2.05b.  */
      for (esc_length = 0, p += octal_0 && *p == '0';
         esc_length < 3 && isodigit (*p);
         ++esc_length, ++p)
      esc_value = esc_value * 8 + octtobin (*p);
      putchar (esc_value);
    }
  else if (*p && strchr ("\"\\abcfnrtv", *p))
    print_esc_char (*p++);
  else if (!posixly_correct && (*p == 'u' || *p == 'U'))
    {
      char esc_char = *p;
      unsigned int uni_value;

      uni_value = 0;
      for (esc_length = (esc_char == 'u' ? 4 : 8), ++p;
         esc_length > 0;
         --esc_length, ++p)
      {
        if (!ISXDIGIT (*p))
          error (EXIT_FAILURE, 0, _("missing hexadecimal number in escape"));
        uni_value = uni_value * 16 + hextobin (*p);
      }

      /* A universal character name shall not specify a character short
       identifier in the range 00000000 through 00000020, 0000007F through
       0000009F, or 0000D800 through 0000DFFF inclusive. A universal
       character name shall not designate a character in the required
       character set.  */
      if ((uni_value <= 0x9f
         && uni_value != 0x24 && uni_value != 0x40 && uni_value != 0x60)
        || (uni_value >= 0xd800 && uni_value <= 0xdfff))
      error (EXIT_FAILURE, 0, _("invalid universal character name \\%c%0*x"),
             esc_char, (esc_char == 'u' ? 4 : 8), uni_value);

      print_unicode_char (stdout, uni_value, 0);
    }
  else
    {
      putchar ('\\');
      if (*p)
      {
        putchar (*p);
        p++;
      }
    }
  return p - escstart - 1;
}

/* Print string STR, evaluating \ escapes. */

static void
print_esc_string (const char *str)
{
  for (; *str; str++)
    if (*str == '\\')
      str += print_esc (str, true);
    else
      putchar (*str);
}

/* Output a % directive.  START is the start of the directive,
   LENGTH is its length, and ARGUMENT is its argument.
   If FIELD_WIDTH or PRECISION is UNSPECIFIED, they are args for
   '*' values in those fields. */

static void
print_direc (const char *start, size_t length, int field_width,
           int precision, const char *argument)
{
  char *p;        /* Null-terminated copy of % directive. */

  p = xmalloc ((unsigned) (length + 1));
  strncpy (p, start, length);
  p[length] = 0;

  switch (p[length - 1])
    {
    case 'd':
    case 'i':
      if (field_width == UNSPECIFIED)
      {
        if (precision == UNSPECIFIED)
          printf (p, xstrtol (argument));
        else
          printf (p, precision, xstrtol (argument));
      }
      else
      {
        if (precision == UNSPECIFIED)
          printf (p, field_width, xstrtol (argument));
        else
          printf (p, field_width, precision, xstrtol (argument));
      }
      break;

    case 'o':
    case 'u':
    case 'x':
    case 'X':
      if (field_width == UNSPECIFIED)
      {
        if (precision == UNSPECIFIED)
          printf (p, xstrtoul (argument));
        else
          printf (p, precision, xstrtoul (argument));
      }
      else
      {
        if (precision == UNSPECIFIED)
          printf (p, field_width, xstrtoul (argument));
        else
          printf (p, field_width, precision, xstrtoul (argument));
      }
      break;

    case 'f':
    case 'e':
    case 'E':
    case 'g':
    case 'G':
      if (field_width == UNSPECIFIED)
      {
        if (precision == UNSPECIFIED)
          printf (p, xstrtod (argument));
        else
          printf (p, precision, xstrtod (argument));
      }
      else
      {
        if (precision == UNSPECIFIED)
          printf (p, field_width, xstrtod (argument));
        else
          printf (p, field_width, precision, xstrtod (argument));
      }
      break;

    case 'c':
      printf (p, *argument);
      break;

    case 's':
      if (field_width == UNSPECIFIED)
      {
        if (precision == UNSPECIFIED)
          printf (p, argument);
        else
          printf (p, precision, argument);
      }
      else
      {
        if (precision == UNSPECIFIED)
          printf (p, field_width, argument);
        else
          printf (p, field_width, precision, argument);
      }
      break;
    }

  free (p);
}

/* Print the text in FORMAT, using ARGV (with ARGC elements) for
   arguments to any `%' directives.
   Return the number of elements of ARGV used.  */

static int
print_formatted (const char *format, int argc, char **argv)
{
  int save_argc = argc;       /* Preserve original value.  */
  const char *f;        /* Pointer into `format'.  */
  const char *direc_start;    /* Start of % directive.  */
  size_t direc_length;        /* Length of % directive.  */
  int field_width;            /* Arg to first '*', or UNSPECIFIED if none. */
  int precision;        /* Arg to second '*', or UNSPECIFIED if none. */

  for (f = format; *f; ++f)
    {
      switch (*f)
      {
      case '%':
        direc_start = f++;
        direc_length = 1;
        field_width = precision = UNSPECIFIED;
        if (*f == '%')
          {
            putchar ('%');
            break;
          }
        if (*f == 'b')
          {
            if (argc > 0)
            {
              print_esc_string (*argv);
              ++argv;
              --argc;
            }
            break;
          }
        while (*f == ' ' || *f == '#' || *f == '+' || *f == '-')
          {
            ++f;
            ++direc_length;
          }
        if (*f == '*')
          {
            ++f;
            ++direc_length;
            if (argc > 0)
            {
              field_width = xstrtoul (*argv);
              if (field_width == UNSPECIFIED)
                error (EXIT_FAILURE, 0, _("invalid field width: %s"),
                     *argv);
              ++argv;
              --argc;
            }
            else
            field_width = 0;
          }
        else
          while (ISDIGIT (*f))
            {
            ++f;
            ++direc_length;
            }
        if (*f == '.')
          {
            ++f;
            ++direc_length;
            if (*f == '*')
            {
              ++f;
              ++direc_length;
              if (argc > 0)
                {
                  precision = xstrtoul (*argv);
                  if (precision == UNSPECIFIED)
                  error (EXIT_FAILURE, 0, _("invalid precision: %s"),
                         *argv);
                  ++argv;
                  --argc;
                }
              else
                precision = 0;
            }
            else
            while (ISDIGIT (*f))
              {
                ++f;
                ++direc_length;
              }
          }
        if (*f == 'l' || *f == 'L' || *f == 'h')
          {
            ++f;
            ++direc_length;
          }
        if (! (*f && strchr ("diouxXfeEgGcs", *f)))
          error (EXIT_FAILURE, 0, _("%%%c: invalid directive"), *f);
        ++direc_length;
        if (argc > 0)
          {
            print_direc (direc_start, direc_length, field_width,
                     precision, *argv);
            ++argv;
            --argc;
          }
        else
          print_direc (direc_start, direc_length, field_width,
                   precision, "");
        break;

      case '\\':
        f += print_esc (f, false);
        break;

      default:
        putchar (*f);
      }
    }

  return save_argc - argc;
}

int
main (int argc, char **argv)
{
  char *format;
  int args_used;

  initialize_main (&argc, &argv);
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  exit_status = 0;

  /* Don't recognize --help or --version if POSIXLY_CORRECT is set.  */
  posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL);
  if (!posixly_correct)
    parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
                  usage, AUTHORS, (char const *) NULL);

  /* The above handles --help and --version.
     Since there is no other invocation of getopt, handle `--' here.  */
  if (1 < argc && STREQ (argv[1], "--"))
    {
      --argc;
      ++argv;
    }

  if (argc <= 1)
    {
      fprintf (stderr, _("Usage: %s format [argument...]\n"), program_name);
      exit (EXIT_FAILURE);
    }

  format = argv[1];
  argc -= 2;
  argv += 2;

  do
    {
      args_used = print_formatted (format, argc, argv);
      argc -= args_used;
      argv += args_used;
    }
  while (args_used > 0 && argc > 0);

  if (argc > 0)
    error (0, 0,
         _("warning: ignoring excess arguments, starting with `%s'"),
         argv[0]);

  exit (exit_status);
}

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