glibc/support/support_quote_blob.c

84 lines
2.6 KiB
C

/* Quote a blob so that it can be used in C literals.
Copyright (C) 2018-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <support/support.h>
#include <support/xmemstream.h>
char *
support_quote_blob (const void *blob, size_t length)
{
struct xmemstream out;
xopen_memstream (&out);
const unsigned char *p = blob;
for (size_t i = 0; i < length; ++i)
{
unsigned char ch = p[i];
/* Use C backslash escapes for those control characters for
which they are defined. */
switch (ch)
{
case '\a':
putc_unlocked ('\\', out.out);
putc_unlocked ('a', out.out);
break;
case '\b':
putc_unlocked ('\\', out.out);
putc_unlocked ('b', out.out);
break;
case '\f':
putc_unlocked ('\\', out.out);
putc_unlocked ('f', out.out);
break;
case '\n':
putc_unlocked ('\\', out.out);
putc_unlocked ('n', out.out);
break;
case '\r':
putc_unlocked ('\\', out.out);
putc_unlocked ('r', out.out);
break;
case '\t':
putc_unlocked ('\\', out.out);
putc_unlocked ('t', out.out);
break;
case '\v':
putc_unlocked ('\\', out.out);
putc_unlocked ('v', out.out);
break;
case '\\':
case '\'':
case '\"':
putc_unlocked ('\\', out.out);
putc_unlocked (ch, out.out);
break;
default:
if (ch < ' ' || ch > '~')
/* Use octal sequences because they are fixed width,
unlike hexadecimal sequences. */
fprintf (out.out, "\\%03o", ch);
else
putc_unlocked (ch, out.out);
}
}
xfclose_memstream (&out);
return out.buffer;
}