This file is printf.def, from which is created printf.c.
It implements the builtin "printf" in Bash.

Copyright (C) 1997-2002 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash 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.

Bash 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 Bash; see the file COPYING.  If not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA

$PRODUCES printf.c

$BUILTIN printf
$FUNCTION printf_builtin
$SHORT_DOC printf format [arguments]
printf formats and prints ARGUMENTS under control of the FORMAT. FORMAT
is a character string which contains three types of objects: plain
characters, which are simply copied to standard output, character escape
sequences which are converted and copied to the standard output, and
format specifications, each of which causes printing of the next successive
argument.  In addition to the standard printf(1) formats, %b means to
expand backslash escape sequences in the corresponding argument, and %q
means to quote the argument in a way that can be reused as shell input.
$END

#include <config.h>

#include "../bashtypes.h"

#include <errno.h>
#if defined (HAVE_LIMITS_H)
#  include <limits.h>
#else
   /* Assume 32-bit ints. */
#  define INT_MAX		2147483647
#  define INT_MIN		(-2147483647-1)
#endif

#include <stdio.h>
#include <chartypes.h>

#ifdef HAVE_INTTYPES_H
#  include <inttypes.h>
#endif

#include "../bashansi.h"

#include "../shell.h"
#include "stdc.h"
#include "bashgetopt.h"
#include "common.h"

#if !defined (PRIdMAX)
#  if HAVE_LONG_LONG
#    define PRIdMAX	"lld"
#  else
#    define PRIdMAX	"ld"
#  endif
#endif

#if !defined (errno)
extern int errno;
#endif

#define PF(f, func) \
  do { \
    if (have_fieldwidth && have_precision) \
      tw += printf(f, fieldwidth, precision, func); \
    else if (have_fieldwidth) \
      tw += printf(f, fieldwidth, func); \
    else if (have_precision) \
      tw += printf(f, precision, func); \
    else \
      tw += printf(f, func); \
  } while (0)

/* We free the buffer used by mklong() if it's `too big'. */
#define PRETURN(value) \
  do \
    { \
      if (conv_bufsize > 4096 ) \
	{ \
	  free(conv_buf); \
	  conv_bufsize = 0; \
	  conv_buf = 0; \
	} \
      fflush (stdout); \
      return (value); \
    } \
  while (0)

#define SKIP1 "#'-+ 0"
#define LENMODS "hjlLtz"

static void printf_erange __P((char *));
static void printstr __P((char *, char *, int, int, int));
static int tescape __P((char *, int, char *, int *, int));
static char *bexpand __P((char *, int, int *, int *));
static char *mklong __P((char *, char *, size_t));
static int getchr __P((void));
static char *getstr __P((void));
static int  getint __P((void));
static intmax_t getintmax __P((void));
static uintmax_t getuintmax __P((void));

#if defined (HAVE_LONG_DOUBLE) && HAVE_DECL_STRTOLD
typedef long double floatmax_t;
#  define FLOATMAX_CONV	"L"
#  define strtofltmax	strtold
#else
typedef double floatmax_t;
#  define FLOATMAX_CONV	""
#  define strtofltmax	strtod
#endif
static floatmax_t getfloatmax __P((void));

static int asciicode __P((void));

static WORD_LIST *garglist;
static int retval;
static int conversion_error;

static char *conv_buf;
static size_t conv_bufsize;

int
printf_builtin (list)
     WORD_LIST *list;
{
  int ch, fieldwidth, precision;
  int have_fieldwidth, have_precision;
  intmax_t tw;
  char convch, thisch, nextch, *format, *modstart, *fmt, *start;

  conversion_error = 0;
  retval = EXECUTION_SUCCESS;

  if (no_options (list))
    return (EX_USAGE);
  list = loptend;	/* skip over possible `--' */

  if (list == 0)
    {
      builtin_usage ();
      return (EX_USAGE);
    }

  if (list->word->word == 0 || list->word->word[0] == '\0')
    return (EXECUTION_SUCCESS);

  format = list->word->word;

  garglist = list->next;

  /* If the format string is empty after preprocessing, return immediately. */
  if (format == 0 || *format == 0)
    return (EXECUTION_SUCCESS);
	  
  /* Basic algorithm is to scan the format string for conversion
     specifications -- once one is found, find out if the field
     width or precision is a '*'; if it is, gather up value.  Note,
     format strings are reused as necessary to use up the provided
     arguments, arguments of zero/null string are provided to use
     up the format string. */
  do
    {
      tw = 0;
      /* find next format specification */
      for (fmt = format; *fmt; fmt++)
	{
	  precision = fieldwidth = 0;
	  have_fieldwidth = have_precision = 0;


	  if (*fmt == '\\')
	    {
	      fmt++;
	      /* A NULL fourth argument to tescape means to not do special
		 processing for \c. */
	      fmt += tescape (fmt, 1, &nextch, (int *)NULL, 0);
	      putchar (nextch);
	      fmt--;	/* for loop will increment it for us again */
	      continue;
	    }

	  if (*fmt != '%')
	    {
	      putchar (*fmt);
	      continue;
	    }

	  /* ASSERT(*fmt == '%') */
	  start = fmt++;

	  if (*fmt == '%')		/* %% prints a % */
	    {
	      putchar ('%');
	      continue;
	    }

	  /* found format specification, skip to field width */
	  for (; *fmt && strchr(SKIP1, *fmt); ++fmt)
	    ;

	  /* Skip optional field width. */
	  if (*fmt == '*')
	    {
	      fmt++;
	      have_fieldwidth = 1;
	      fieldwidth = getint ();
	    }
	  else
	    while (DIGIT (*fmt))
	      fmt++;

	  /* Skip optional '.' and precision */
	  if (*fmt == '.')
	    {
	      ++fmt;
	      if (*fmt == '*')
		{
		  fmt++;
		  have_precision = 1;
		  precision = getint ();
		}
	      else
		while (DIGIT (*fmt))
		  fmt++;
	    }

	  /* skip possible format modifiers */
	  modstart = fmt;
	  while (*fmt && strchr (LENMODS, *fmt))
	    fmt++;
	    
	  if (*fmt == 0)
	    {
	      builtin_error ("`%s': missing format character", start);
	      PRETURN (EXECUTION_FAILURE);
	    }

	  convch = *fmt;
	  thisch = modstart[0];
	  nextch = modstart[1];
	  modstart[0] = convch;
	  modstart[1] = '\0';

	  switch(convch)
	    {
	    case 'c':
	      {
		char p;

		p = getchr ();
		PF(start, p);
		break;
	      }

	    case 's':
	      {
		char *p;

		p = getstr ();
		PF(start, p);
		break;
	      }

	    case 'n':
	      {
		char *var;

		var = getstr ();
		if (var && *var)
		  {
		    if (legal_identifier (var))
		      bind_var_to_int (var, tw);
		    else
		      {
			sh_invalidid (var);
			PRETURN (EXECUTION_FAILURE);
		      }
		  }
		break;
	      }

	    case 'b':		/* expand escapes in argument */
	      {
		char *p, *xp;
		int rlen;

		p = getstr ();
		ch = rlen = 0;
		xp = bexpand (p, strlen (p), &ch, &rlen);

		if (xp)
		  {
		    /* Have to use printstr because of possible NUL bytes
		       in XP -- printf does not handle that well. */
		    printstr (start, xp, rlen, fieldwidth, precision);
		    free (xp);
		  }

		if (ch)
		  PRETURN (retval);
		break;
	      }

	    case 'q':		/* print with shell quoting */
	      {
		char *p, *xp;

		p = getstr ();
		if (ansic_shouldquote (p))
		  xp = ansic_quote (p, 0, (int *)0);
		else
		  xp = sh_backslash_quote (p);
		if (xp)
		  {
		    /* Use printstr to get fieldwidth and precision right. */
		    printstr (start, xp, strlen (xp), fieldwidth, precision);
		    free (xp);
		  }
		break;
	      }

	    case 'd':
	    case 'i':
	      {
		char *f;
		long p;
		intmax_t pp;

		p = pp = getintmax ();
		if (p != pp)
		  {
		    f = mklong (start, PRIdMAX, sizeof (PRIdMAX) - 2);
		    PF (f, pp);
		  }
		else
		  {
		    /* Optimize the common case where the integer fits
		       in "long".  This also works around some long
		       long and/or intmax_t library bugs in the common
		       case, e.g. glibc 2.2 x86.  */
		    f = mklong (start, "l", 1);
		    PF (f, p);
		  }
		break;
	      }

	    case 'o':
	    case 'u':
	    case 'x':
	    case 'X':
	      {
		char *f;
		unsigned long p;
		uintmax_t pp;

		p = pp = getuintmax ();
		if (p != pp)
		  {
		    f = mklong (start, PRIdMAX, sizeof (PRIdMAX) - 2);
		    PF (f, pp);
		  }
		else
		  {
		    f = mklong (start, "l", 1);
		    PF (f, p);
		  }
		break;
	      }

	    case 'e':
	    case 'E':
	    case 'f':
	    case 'F':
	    case 'g':
	    case 'G':
#if defined (HAVE_PRINTF_A_FORMAT)
	    case 'a':
	    case 'A':
#endif
	      {
		char *f;
		floatmax_t p;

		p = getfloatmax ();
		f = mklong (start, FLOATMAX_CONV, sizeof(FLOATMAX_CONV) - 1);
		PF (f, p);
		break;
	      }

	    /* We don't output unrecognized format characters; we print an
	       error message and return a failure exit status. */
	    default:
	      builtin_error ("`%c': invalid format character", convch);
	      PRETURN (EXECUTION_FAILURE);
	    }

	  modstart[0] = thisch;
	  modstart[1] = nextch;
	}
    }
  while (garglist && garglist != list->next);

  if (conversion_error)
    retval = EXECUTION_FAILURE;

  PRETURN (retval);
}

static void
printf_erange (s)
     char *s;
{
  builtin_error ("warning: %s: %s", s, strerror(ERANGE));
}

/* We duplicate a lot of what printf(3) does here. */
static void
printstr (fmt, string, len, fieldwidth, precision)
     char *fmt;			/* format */
     char *string;		/* expanded string argument */
     int len;			/* length of expanded string */
     int fieldwidth;		/* argument for width of `*' */
     int precision;		/* argument for precision of `*' */
{
#if 0
  char *s;
#endif
  int padlen, nc, ljust, i;
  int fw, pr;			/* fieldwidth and precision */

  if (string == 0)		/* Process even with *string == '\0', valid %b data */
    return;

#if 0
  s = fmt;
#endif
  if (*fmt == '%')
    fmt++;

  ljust = fw = 0;
  pr = -1;

  /* skip flags */
  while (strchr (SKIP1, *fmt))
    {
      if (*fmt == '-')
	ljust = 1;
      fmt++;
    }

  /* get fieldwidth, if present */
  if (*fmt == '*')
    {
      fmt++;
      fw = fieldwidth;
      if (fw < 0)
	{
	  fw = -fw;
	  ljust = 1;
	}
    }
  else if (DIGIT (*fmt))
    {
      fw = *fmt++ - '0';
      while (DIGIT (*fmt))
	fw = (fw * 10) + (*fmt++ - '0');
    }

  /* get precision, if present */
  if (*fmt == '.')
    {
      fmt++;
      if (*fmt == '*')
	{
	  fmt++;
	  pr = precision;
	}
      else if (DIGIT (*fmt))
	{
	  pr = *fmt++ - '0';
	  while (DIGIT (*fmt))
	    pr = (pr * 10) + (*fmt++ - '0');
	}
    }

#if 0
  /* If we remove this, get rid of `s'. */
  if (*fmt != 'b' && *fmt != 'q')
    {
      internal_error ("format parsing problem: %s", s);
      fw = pr = 0;
    }
#endif

  /* chars from string to print */
  nc = (pr >= 0 && pr <= len) ? pr : len;

  padlen = fw - nc;
  if (padlen < 0)
    padlen = 0;
  if (ljust)
    padlen = -padlen;

  /* leading pad characters */
  for (; padlen > 0; padlen--)
    putchar (' ');

  /* output NC characters from STRING */
  for (i = 0; i < nc; i++)
    putchar (string[i]);

  /* output any necessary trailing padding */
  for (; padlen < 0; padlen++)
    putchar (' ');
}
  
/* Convert STRING by expanding the escape sequences specified by the
   POSIX standard for printf's `%b' format string.  If SAWC is non-null,
   recognize `\c' and use that as a string terminator.  If we see \c, set
   *SAWC to 1 before returning.  LEN is the length of STRING. */

/* Translate a single backslash-escape sequence starting at ESTART (the
   character after the backslash) and return the number of characters
   consumed by the sequence.  CP is the place to return the translated
   value.  *SAWC is set to 1 if the escape sequence was \c, since that means
   to short-circuit the rest of the processing.  If SAWC is null, we don't
   do the \c short-circuiting, and \c is treated as an unrecognized escape
   sequence. 
   %b format must handle \\0[0-7]{1,3} but printf fmt must only handle \\[0-7]{1,3}
   Use incoming parameter to print \0000 differently for each caller.  */
static int
tescape (estart, trans_squote, cp, sawc, b_format)
     char *estart;
     int trans_squote;
     char *cp;
     int *sawc;
     int b_format;
{
  register char *p;
  int temp, c, evalue;

  p = estart;

  switch (c = *p++)
    {
#if defined (__STDC__)
      case 'a': *cp = '\a'; break;
#else
      case 'a': *cp = '\007'; break;
#endif

      case 'b': *cp = '\b'; break;

      case 'e':
      case 'E': *cp = '\033'; break;	/* ESC -- non-ANSI */

      case 'f': *cp = '\f'; break;

      case 'n': *cp = '\n'; break;

      case 'r': *cp = '\r'; break;

      case 't': *cp = '\t'; break;

      case 'v': *cp = '\v'; break;

      /* %b octal constants are `\0' followed by one, two, or three
	 octal digits... */
      case '0':
      /* but, as an extension, the other echo-like octal escape
	 sequences are supported as well. */
      case '1': case '2': case '3': case '4':
      case '5': case '6': case '7':
        if (b_format)
     	  temp = 2+(c=='0');
        else
          temp = 2;		/* limit to \000 not \0000 like %b */
	for (evalue = c - '0'; ISOCTAL (*p) && temp--; p++)
	  evalue = (evalue * 8) + OCTVALUE (*p);
	*cp = evalue & 0xFF;
	break;

      /* And, as another extension, we allow \xNNN, where each N is a
	 hex digit. */
      case 'x':
	for (temp = 2, evalue = 0; ISXDIGIT ((unsigned char)*p) && temp--; p++)
	  evalue = (evalue * 16) + HEXVALUE (*p);
	if (temp == 2)
	  {
	    builtin_error ("missing hex digit for \\x");
	    *cp = '\\';
	    return 0;
	  }
	*cp = evalue & 0xFF;
	break;

      case '\\':	/* \\ -> \ */
	*cp = c;
	break;

      case '\'':	/* TRANS_SQUOTE != 0 means \' -> ' */
	if (trans_squote)
	  *cp = c;
	else
	  {
	    *cp = '\\';
	    return 0;
	  }
	break;

      case 'c':
	if (sawc)
	  {
	    *sawc = 1;
	    break;
	  }
      /* other backslash escapes are passed through unaltered */
      default:
	*cp = '\\';
	return 0;
      }
  return (p - estart);
}

static char *
bexpand (string, len, sawc, lenp)
     char *string;
     int len, *sawc, *lenp;
{
  int temp;
  char *ret, *r, *s, c;

  if (string == 0 || *string == '\0')
    {
      if (sawc)
	*sawc = 0;
      if (lenp)
	*lenp = 0;
      return ((char *)NULL);
    }

  ret = (char *)xmalloc (len + 1);
  for (r = ret, s = string; s && *s; )
    {
      c = *s++;
      if (c != '\\' || *s == '\0')
	{
	  *r++ = c;
	  continue;
	}
      temp = 0;
      s += tescape (s, 0, &c, &temp, 1);
      if (temp)
	{
	  if (sawc)
	    *sawc = 1;
	  break;
	}

      *r++ = c;
    }

  *r = '\0';
  if (lenp)
    *lenp = r - ret;
  return ret;
}

static char *
mklong (str, modifiers, mlen)
     char *str;
     char *modifiers;
     size_t mlen;
{
  size_t len, slen;

  slen = strlen (str);
  len = slen + mlen + 1;

  if (len > conv_bufsize)
    {
      conv_bufsize = (((len + 1023) >> 10) << 10);
      conv_buf = (char *)xrealloc (conv_buf, conv_bufsize);
    }

  FASTCOPY (str, conv_buf, slen - 1);
  FASTCOPY (modifiers, conv_buf + slen - 1, mlen);

  conv_buf[len - 2] = str[slen - 1];
  conv_buf[len - 1] = '\0';
  return (conv_buf);
}

static int
getchr ()
{
  int ret;

  if (garglist == 0)
    return ('\0');

  ret = (int)garglist->word->word[0];
  garglist = garglist->next;
  return ret;
}

static char *
getstr ()
{
  char *ret;

  if (garglist == 0)
    return ("");

  ret = garglist->word->word;
  garglist = garglist->next;
  return ret;
}

static int
getint ()
{
  intmax_t ret;

  ret = getintmax ();

  if (ret > INT_MAX)
    {
      printf_erange (garglist->word->word);
      ret = INT_MAX;
    }
  else if (ret < INT_MIN)
    {
      printf_erange (garglist->word->word);
      ret = INT_MIN;
    }

  return ((int)ret);
}

static intmax_t
getintmax ()
{
  intmax_t ret;
  char *ep;

  if (garglist == 0)
    return (0);

  if (garglist->word->word[0] == '\'' || garglist->word->word[0] == '"')
    return asciicode ();

  errno = 0;
  ret = strtoimax (garglist->word->word, &ep, 0);

  if (*ep)
    {
      sh_invalidnum (garglist->word->word);
      /* POSIX.2 says ``...a diagnostic message shall be written to standard
	 error, and the utility shall not exit with a zero exit status, but
	 shall continue processing any remaining operands and shall write the
         value accumulated at the time the error was detected to standard
	 output.''  Yecch. */
      ret = 0;
      conversion_error = 1;
    }
  else if (errno == ERANGE)
    printf_erange (garglist->word->word);

  garglist = garglist->next;
  return (ret);
}

static uintmax_t
getuintmax ()
{
  uintmax_t ret;
  char *ep;

  if (garglist == 0)
    return (0);

  if (garglist->word->word[0] == '\'' || garglist->word->word[0] == '"')
    return asciicode ();

  errno = 0;
  ret = strtoumax (garglist->word->word, &ep, 0);
  
  if (*ep)
    {
      sh_invalidnum (garglist->word->word);
      /* Same POSIX.2 conversion error requirements as getintmax(). */
      ret = 0;
      conversion_error = 1;
    }
  else if (errno == ERANGE)
    printf_erange (garglist->word->word);

  garglist = garglist->next;
  return (ret);
}

static floatmax_t
getfloatmax ()
{
  floatmax_t ret;
  char *ep;

  if (garglist == 0)
    return (0);

  if (garglist->word->word[0] == '\'' || garglist->word->word[0] == '"')
    return asciicode ();

  errno = 0;
  ret = strtofltmax (garglist->word->word, &ep);

  if (*ep)
    {
      sh_invalidnum (garglist->word->word);
      /* Same thing about POSIX.2 conversion error requirements. */
      ret = 0;
      conversion_error = 1;
    }
  else if (errno == ERANGE)
    printf_erange (garglist->word->word);

  garglist = garglist->next;
  return (ret);
}

/* NO check is needed for garglist here. */
static int
asciicode ()
{
  register int ch;

  ch = garglist->word->word[1];
  garglist = garglist->next;
  return (ch);
}