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Languguage OS II Version 10-94 (Knowledge Media)(1994).ISO
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shllutil.lha
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shellutils-1.8
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src
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printf.c
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1992-06-04
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/* printf - format and print data
Copyright (C) 1990, 1991 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., 675 Mass Ave, Cambridge, MA 02139, 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
\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> */
#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include "system.h"
#ifndef STDC_HEADERS
double strtod ();
long strtol ();
unsigned long strtoul ();
#endif
#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')
char *xmalloc ();
double xstrtod ();
int print_esc ();
int print_formatted ();
long xstrtol ();
unsigned long xstrtoul ();
void error ();
void print_direc ();
void print_esc_char ();
void print_esc_string ();
void verify ();
/* The name this program was run with. */
char *program_name;
/* The value to return to the calling program. */
int exit_status;
void
main (argc, argv)
int argc;
char **argv;
{
char *format;
int args_used;
program_name = argv[0];
exit_status = 0;
if (argc == 1)
{
fprintf (stderr, "Usage: %s format [argument...]\n", program_name);
exit (1);
}
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);
exit (exit_status);
}
/* Print the text in FORMAT, using ARGV (with ARGC elements) for
arguments to any `%' directives.
Return the number of elements of ARGV used. */
int
print_formatted (format, argc, argv)
char *format;
int argc;
char **argv;
{
int save_argc = argc; /* Preserve original value. */
char *f; /* Pointer into `format'. */
char *direc_start; /* Start of % directive. */
int direc_length; /* Length of % directive. */
int field_width; /* Arg to first '*', or -1 if none. */
int precision; /* Arg to second '*', or -1 if none. */
for (f = format; *f; ++f)
{
switch (*f)
{
case '%':
direc_start = f++;
direc_length = 1;
field_width = precision = -1;
if (*f == '%')
{
putchar ('%');
break;
}
if (*f == 'b')
{
if (argc > 0)
{
print_esc_string (*argv);
++argv;
--argc;
}
break;
}
if (index ("-+ #", *f))
{
++f;
++direc_length;
}
if (*f == '*')
{
++f;
++direc_length;
if (argc > 0)
{
field_width = xstrtoul (*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);
++argv;
--argc;
}
else
precision = 0;
}
else
while (isdigit (*f))
{
++f;
++direc_length;
}
}
if (*f == 'l' || *f == 'L' || *f == 'h')
{
++f;
++direc_length;
}
if (!index ("diouxXfeEgGcs", *f))
error (1, 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);
break;
default:
putchar (*f);
}
}
return save_argc - argc;
}
/* Print a \ escape sequence starting at ESCSTART.
Return the number of characters in the escape sequence
besides the backslash. */
int
print_esc (escstart)
char *escstart;
{
register char *p = escstart + 1;
int esc_value = 0; /* Value of \nnn escape. */
int esc_length; /* Length of \nnn escape. */
/* \0ooo and \xhhh escapes have maximum length of 3 chars. */
if (*p == 'x')
{
for (esc_length = 0, ++p;
esc_length < 3 && isxdigit (*p);
++esc_length, ++p)
esc_value = esc_value * 16 + hextobin (*p);
if (esc_length == 0)
error (1, 0, "missing hexadecimal number in escape");
putchar (esc_value);
}
else if (*p == '0')
{
for (esc_length = 0, ++p;
esc_length < 3 && isodigit (*p);
++esc_length, ++p)
esc_value = esc_value * 8 + octtobin (*p);
putchar (esc_value);
}
else if (index ("\"\\abcfnrtv", *p))
print_esc_char (*p++);
else
error (1, 0, "\\%c: invalid escape", *p);
return p - escstart - 1;
}
/* Output a single-character \ escape. */
void
print_esc_char (c)
char c;
{
switch (c)
{
case 'a': /* Alert. */
putchar (7);
break;
case 'b': /* Backspace. */
putchar (8);
break;
case 'c': /* Cancel the rest of the output. */
exit (0);
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 string STR, evaluating \ escapes. */
void
print_esc_string (str)
char *str;
{
for (; *str; str++)
if (*str == '\\')
str += print_esc (str);
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 non-negative, they are args for
'*' values in those fields. */
void
print_direc (start, length, field_width, precision, argument)
char *start;
int length;
int field_width;
int precision;
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 < 0)
{
if (precision < 0)
printf (p, xstrtol (argument));
else
printf (p, precision, xstrtol (argument));
}
else
{
if (precision < 0)
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 < 0)
{
if (precision < 0)
printf (p, xstrtoul (argument));
else
printf (p, precision, xstrtoul (argument));
}
else
{
if (precision < 0)
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 < 0)
{
if (precision < 0)
printf (p, xstrtod (argument));
else
printf (p, precision, xstrtod (argument));
}
else
{
if (precision < 0)
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 < 0)
{
if (precision < 0)
printf (p, argument);
else
printf (p, precision, argument);
}
else
{
if (precision < 0)
printf (p, field_width, argument);
else
printf (p, field_width, precision, argument);
}
break;
}
free (p);
}
unsigned long
xstrtoul (s)
char *s;
{
char *end;
unsigned long val;
errno = 0;
val = strtoul (s, &end, 0);
verify (s, end);
return val;
}
long
xstrtol (s)
char *s;
{
char *end;
long val;
errno = 0;
val = strtol (s, &end, 0);
verify (s, end);
return val;
}
double
xstrtod (s)
char *s;
{
char *end;
double val;
errno = 0;
val = strtod (s, &end);
verify (s, end);
return val;
}
void
verify (s, end)
char *s, *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;
}
}