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/* -*- 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 _STRING_C_
#define _STRING_C_
#include "string.h"
/** @file 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 len 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 void _stp_text_str(char *outstr, char *in, int len, int quoted, int user)
{
char c, *out = outstr;
if (len <= 0 || len > MAXSTRINGLEN-1)
len = MAXSTRINGLEN-1;
if (quoted) {
len = max(len, 5) - 2;
*out++ = '"';
}
if (user) {
if (!access_ok(VERIFY_READ, (char __user *)in, 1))
goto bad;
if (__stp_get_user(c, in))
goto bad;
} else
c = *in;
while (c && len > 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 (len < 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;
}
}
len -= num;
in++;
if (user) {
if (__stp_get_user(c, in))
goto bad;
} else
c = *in;
}
if (quoted) {
if (c) {
out = out - 3 + len;
*out++ = '"';
*out++ = '.';
*out++ = '.';
*out++ = '.';
} else
*out++ = '"';
}
*out = '\0';
return;
bad:
strlcpy (outstr, "<unknown>", len);
}
/** @} */
#endif /* _STRING_C_ */
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