| 1 | /* Implement the vsnprintf function. |
| 2 | Copyright (C) 2003 Free Software Foundation, Inc. |
| 3 | Written by Kaveh R. Ghazi <ghazi@caip.rutgers.edu>. |
| 4 | |
| 5 | This file is part of the libiberty library. This library is free |
| 6 | software; you can redistribute it and/or modify it under the |
| 7 | terms of the GNU General Public License as published by the |
| 8 | Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | This library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU CC; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 19 | |
| 20 | As a special exception, if you link this library with files |
| 21 | compiled with a GNU compiler to produce an executable, this does not cause |
| 22 | the resulting executable to be covered by the GNU General Public License. |
| 23 | This exception does not however invalidate any other reasons why |
| 24 | the executable file might be covered by the GNU General Public License. */ |
| 25 | |
| 26 | /* |
| 27 | |
| 28 | @deftypefn Supplemental int vsnprintf (char *@var{buf}, size_t @var{n}, const char *@var{format}, va_list @var{ap}) |
| 29 | |
| 30 | This function is similar to vsprintf, but it will print at most |
| 31 | @var{n} characters. On error the return value is -1, otherwise it |
| 32 | returns the number of characters that would have been printed had |
| 33 | @var{n} been sufficiently large, regardless of the actual value of |
| 34 | @var{n}. Note some pre-C99 system libraries do not implement this |
| 35 | correctly so users cannot generally rely on the return value if the |
| 36 | system version of this function is used. |
| 37 | |
| 38 | @end deftypefn |
| 39 | |
| 40 | */ |
| 41 | |
| 42 | #include "config.h" |
| 43 | #include "ansidecl.h" |
| 44 | |
| 45 | #ifdef ANSI_PROTOTYPES |
| 46 | #include <stdarg.h> |
| 47 | #else |
| 48 | #include <varargs.h> |
| 49 | #endif |
| 50 | #ifdef HAVE_STRING_H |
| 51 | #include <string.h> |
| 52 | #endif |
| 53 | #ifdef HAVE_STDLIB_H |
| 54 | #include <stdlib.h> |
| 55 | #endif |
| 56 | |
| 57 | #include "libiberty.h" |
| 58 | |
| 59 | /* This implementation relies on a working vasprintf. */ |
| 60 | int |
| 61 | vsnprintf (s, n, format, ap) |
| 62 | char * s; |
| 63 | size_t n; |
| 64 | const char *format; |
| 65 | va_list ap; |
| 66 | { |
| 67 | char *buf = 0; |
| 68 | int result = vasprintf (&buf, format, ap); |
| 69 | |
| 70 | if (!buf) |
| 71 | return -1; |
| 72 | if (result < 0) |
| 73 | { |
| 74 | free (buf); |
| 75 | return -1; |
| 76 | } |
| 77 | |
| 78 | result = strlen (buf); |
| 79 | if (n > 0) |
| 80 | { |
| 81 | if ((long) n > result) |
| 82 | memcpy (s, buf, result+1); |
| 83 | else |
| 84 | { |
| 85 | memcpy (s, buf, n-1); |
| 86 | s[n - 1] = 0; |
| 87 | } |
| 88 | } |
| 89 | free (buf); |
| 90 | return result; |
| 91 | } |
| 92 | |
| 93 | #ifdef TEST |
| 94 | /* Set the buffer to a known state. */ |
| 95 | #define CLEAR(BUF) do { memset ((BUF), 'X', sizeof (BUF)); (BUF)[14] = '\0'; } while (0) |
| 96 | /* For assertions. */ |
| 97 | #define VERIFY(P) do { if (!(P)) abort(); } while (0) |
| 98 | |
| 99 | static int ATTRIBUTE_PRINTF_3 |
| 100 | checkit VPARAMS ((char *s, size_t n, const char *format, ...)) |
| 101 | { |
| 102 | int result; |
| 103 | VA_OPEN (ap, format); |
| 104 | VA_FIXEDARG (ap, char *, s); |
| 105 | VA_FIXEDARG (ap, size_t, n); |
| 106 | VA_FIXEDARG (ap, const char *, format); |
| 107 | result = vsnprintf (s, n, format, ap); |
| 108 | VA_CLOSE (ap); |
| 109 | return result; |
| 110 | } |
| 111 | |
| 112 | extern int main PARAMS ((void)); |
| 113 | int |
| 114 | main () |
| 115 | { |
| 116 | char buf[128]; |
| 117 | int status; |
| 118 | |
| 119 | CLEAR (buf); |
| 120 | status = checkit (buf, 10, "%s:%d", "foobar", 9); |
| 121 | VERIFY (status==8 && memcmp (buf, "foobar:9\0XXXXX\0", 15) == 0); |
| 122 | |
| 123 | CLEAR (buf); |
| 124 | status = checkit (buf, 9, "%s:%d", "foobar", 9); |
| 125 | VERIFY (status==8 && memcmp (buf, "foobar:9\0XXXXX\0", 15) == 0); |
| 126 | |
| 127 | CLEAR (buf); |
| 128 | status = checkit (buf, 8, "%s:%d", "foobar", 9); |
| 129 | VERIFY (status==8 && memcmp (buf, "foobar:\0XXXXXX\0", 15) == 0); |
| 130 | |
| 131 | CLEAR (buf); |
| 132 | status = checkit (buf, 7, "%s:%d", "foobar", 9); |
| 133 | VERIFY (status==8 && memcmp (buf, "foobar\0XXXXXXX\0", 15) == 0); |
| 134 | |
| 135 | CLEAR (buf); |
| 136 | status = checkit (buf, 6, "%s:%d", "foobar", 9); |
| 137 | VERIFY (status==8 && memcmp (buf, "fooba\0XXXXXXXX\0", 15) == 0); |
| 138 | |
| 139 | CLEAR (buf); |
| 140 | status = checkit (buf, 2, "%s:%d", "foobar", 9); |
| 141 | VERIFY (status==8 && memcmp (buf, "f\0XXXXXXXXXXXX\0", 15) == 0); |
| 142 | |
| 143 | CLEAR (buf); |
| 144 | status = checkit (buf, 1, "%s:%d", "foobar", 9); |
| 145 | VERIFY (status==8 && memcmp (buf, "\0XXXXXXXXXXXXX\0", 15) == 0); |
| 146 | |
| 147 | CLEAR (buf); |
| 148 | status = checkit (buf, 0, "%s:%d", "foobar", 9); |
| 149 | VERIFY (status==8 && memcmp (buf, "XXXXXXXXXXXXXX\0", 15) == 0); |
| 150 | |
| 151 | return 0; |
| 152 | } |
| 153 | #endif /* TEST */ |