/* -*- linux-c -*-
* String Functions
* Copyright (C) 2005, 2006, 2007, 2009 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _STP_STRING_C_
#define _STP_STRING_C_
#include "stp_string.h"
/** @file stp_string.c
* @brief Implements string functions.
*/
/** @addtogroup string String Functions
*
* @{
*/
/** Sprintf into a string.
* Like printf, except output goes into a string.
*
* NB: these are script language printf formatting directives, where
* %d ints are 64-bits etc, so we can't use gcc level attribute printf
* to type-check the arguments.
*
* @param str string
* @param fmt A printf-style format string followed by a
* variable number of args.
*/
static int _stp_snprintf(char *buf, size_t size, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = _stp_vsnprintf(buf,size,fmt,args);
va_end(args);
return i;
}
static int _stp_vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
unsigned i = _stp_vsnprintf(buf,size,fmt,args);
return (i >= size) ? (size - 1) : i;
}
/** Return a printable text string.
*
* Takes a string, and any ASCII characters that are not printable are
* replaced by the corresponding escape sequence in the returned
* string.
*
* @param outstr Output string pointer
* @param in Input string pointer
* @param inlen Maximum length of string to read not including terminating 0.
* @param outlen Maximum length of string to return not including terminating 0.
* 0 means MAXSTRINGLEN.
* @param quoted Put double quotes around the string. If input string is truncated
* in will have "..." after the second quote.
* @param user Set this to indicate the input string pointer is a userspace pointer.
*/
static int _stp_text_str(char *outstr, char *in, int inlen, int outlen, int quoted, int user)
{
char c = '\0', *out = outstr;
if (inlen <= 0 || inlen > MAXSTRINGLEN-1)
inlen = MAXSTRINGLEN-1;
if (outlen <= 0 || outlen > MAXSTRINGLEN-1)
outlen = MAXSTRINGLEN-1;
if (quoted) {
outlen = max(outlen, 5) - 2;
*out++ = '"';
}
if (user) {
if (_stp_read_address(c, in, USER_DS))
goto bad;
} else
c = *in;
while (c && inlen > 0 && outlen > 0) {
int num = 1;
if (isprint(c) && isascii(c)
&& c != '"' && c != '\\') /* quoteworthy characters */
*out++ = c;
else {
switch (c) {
case '\a':
case '\b':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
case '"':
case '\\':
num = 2;
break;
default:
num = 4;
break;
}
if (outlen < num)
break;
*out++ = '\\';
switch (c) {
case '\a':
*out++ = 'a';
break;
case '\b':
*out++ = 'b';
break;
case '\f':
*out++ = 'f';
break;
case '\n':
*out++ = 'n';
break;
case '\r':
*out++ = 'r';
break;
case '\t':
*out++ = 't';
break;
case '\v':
*out++ = 'v';
break;
case '"':
*out++ = '"';
break;
case '\\':
*out++ = '\\';
break;
default: /* output octal representation */
*out++ = to_oct_digit((c >> 6) & 03);
*out++ = to_oct_digit((c >> 3) & 07);
*out++ = to_oct_digit(c & 07);
break;
}
}
outlen -= num;
inlen--;
in++;
if (user) {
if (_stp_read_address(c, in, USER_DS))
goto bad;
} else
c = *in;
}
if (quoted) {
if (c && inlen > 0) {
out = out - 3 + outlen;
*out++ = '"';
*out++ = '.';
*out++ = '.';
*out++ = '.';
} else
*out++ = '"';
}
*out = '\0';
return 0;
bad:
strlcpy (outstr, "<unknown>", outlen);
return -1; // PR15044
}
/**
* Convert a UTF-32 character into a UTF-8 string.
*
* @param buf The output buffer.
* @param size The size of the output buffer.
* @param c The character to convert.
*
* @return The number of bytes written (not counting \0),
* 0 if there's not enough room for the full character,
* or < 0 for invalid characters (with buf untouched).
*/
static int _stp_convert_utf32(char* buf, int size, u32 c)
{
int i, n;
/* 0xxxxxxx */
if (c < 0x7F)
n = 1;
/* 110xxxxx 10xxxxxx */
else if (c < 0x7FF)
n = 2;
/* UTF-16 surrogates are not valid by themselves.
* XXX We could decide to be lax and just encode it anyway...
*/
else if (c >= 0xD800 && c <= 0xDFFF)
return -EINVAL;
/* 1110xxxx 10xxxxxx 10xxxxxx */
else if (c < 0xFFFF)
n = 3;
/* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
else if (c < 0x10FFFF)
n = 4;
/* The original UTF-8 design could go up to 0x7FFFFFFF, but RFC 3629
* sets the upperbound to 0x10FFFF; thus all higher values are errors.
*/
else
return -EINVAL;
if (size < n + 1)
return 0;
buf[n] = '\0';
if (n == 1)
buf[0] = c;
else {
u8 msb = ((1 << n) - 1) << (8 - n);
for (i = n - 1; i > 0; --i) {
buf[i] = 0x80 | (c & 0x3F);
c >>= 6;
}
buf[0] = msb | c;
}
return n;
}
/** @} */
#endif /* _STP_STRING_C_ */