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- // Copyright 2013 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- //
- // This file defines utility functions for working with strings.
- #ifndef BUTIL_STRINGS_STRING_UTIL_H_
- #define BUTIL_STRINGS_STRING_UTIL_H_
- #include <ctype.h>
- #include <stdarg.h> // va_list
- #include <string>
- #include <vector>
- #include "butil/base_export.h"
- #include "butil/basictypes.h"
- #include "butil/compiler_specific.h"
- #include "butil/strings/string16.h"
- #include "butil/strings/string_piece.h" // For implicit conversions.
- namespace butil {
- // C standard-library functions like "strncasecmp" and "snprintf" that aren't
- // cross-platform are provided as "butil::strncasecmp", and their prototypes
- // are listed below. These functions are then implemented as inline calls
- // to the platform-specific equivalents in the platform-specific headers.
- // Compares the two strings s1 and s2 without regard to case using
- // the current locale; returns 0 if they are equal, 1 if s1 > s2, and -1 if
- // s2 > s1 according to a lexicographic comparison.
- int strcasecmp(const char* s1, const char* s2);
- // Compares up to count characters of s1 and s2 without regard to case using
- // the current locale; returns 0 if they are equal, 1 if s1 > s2, and -1 if
- // s2 > s1 according to a lexicographic comparison.
- int strncasecmp(const char* s1, const char* s2, size_t count);
- // Same as strncmp but for char16 strings.
- int strncmp16(const char16* s1, const char16* s2, size_t count);
- // Wrapper for vsnprintf that always null-terminates and always returns the
- // number of characters that would be in an untruncated formatted
- // string, even when truncation occurs.
- int vsnprintf(char* buffer, size_t size, const char* format, va_list arguments)
- PRINTF_FORMAT(3, 0);
- // Some of these implementations need to be inlined.
- // We separate the declaration from the implementation of this inline
- // function just so the PRINTF_FORMAT works.
- inline int snprintf(char* buffer, size_t size, const char* format, ...)
- PRINTF_FORMAT(3, 4);
- inline int snprintf(char* buffer, size_t size, const char* format, ...) {
- va_list arguments;
- va_start(arguments, format);
- int result = vsnprintf(buffer, size, format, arguments);
- va_end(arguments);
- return result;
- }
- // BSD-style safe and consistent string copy functions.
- // Copies |src| to |dst|, where |dst_size| is the total allocated size of |dst|.
- // Copies at most |dst_size|-1 characters, and always NULL terminates |dst|, as
- // long as |dst_size| is not 0. Returns the length of |src| in characters.
- // If the return value is >= dst_size, then the output was truncated.
- // NOTE: All sizes are in number of characters, NOT in bytes.
- BUTIL_EXPORT size_t strlcpy(char* dst, const char* src, size_t dst_size);
- BUTIL_EXPORT size_t wcslcpy(wchar_t* dst, const wchar_t* src, size_t dst_size);
- // Scan a wprintf format string to determine whether it's portable across a
- // variety of systems. This function only checks that the conversion
- // specifiers used by the format string are supported and have the same meaning
- // on a variety of systems. It doesn't check for other errors that might occur
- // within a format string.
- //
- // Nonportable conversion specifiers for wprintf are:
- // - 's' and 'c' without an 'l' length modifier. %s and %c operate on char
- // data on all systems except Windows, which treat them as wchar_t data.
- // Use %ls and %lc for wchar_t data instead.
- // - 'S' and 'C', which operate on wchar_t data on all systems except Windows,
- // which treat them as char data. Use %ls and %lc for wchar_t data
- // instead.
- // - 'F', which is not identified by Windows wprintf documentation.
- // - 'D', 'O', and 'U', which are deprecated and not available on all systems.
- // Use %ld, %lo, and %lu instead.
- //
- // Note that there is no portable conversion specifier for char data when
- // working with wprintf.
- //
- // This function is intended to be called from butil::vswprintf.
- BUTIL_EXPORT bool IsWprintfFormatPortable(const wchar_t* format);
- // ASCII-specific tolower. The standard library's tolower is locale sensitive,
- // so we don't want to use it here.
- template <class Char> inline Char ToLowerASCII(Char c) {
- return (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c;
- }
- // ASCII-specific toupper. The standard library's toupper is locale sensitive,
- // so we don't want to use it here.
- template <class Char> inline Char ToUpperASCII(Char c) {
- return (c >= 'a' && c <= 'z') ? (c + ('A' - 'a')) : c;
- }
- // Function objects to aid in comparing/searching strings.
- template<typename Char> struct CaseInsensitiveCompare {
- public:
- bool operator()(Char x, Char y) const {
- // TODO(darin): Do we really want to do locale sensitive comparisons here?
- // See http://crbug.com/24917
- return tolower(x) == tolower(y);
- }
- };
- template<typename Char> struct CaseInsensitiveCompareASCII {
- public:
- bool operator()(Char x, Char y) const {
- return ToLowerASCII(x) == ToLowerASCII(y);
- }
- };
- // These threadsafe functions return references to globally unique empty
- // strings.
- //
- // It is likely faster to construct a new empty string object (just a few
- // instructions to set the length to 0) than to get the empty string singleton
- // returned by these functions (which requires threadsafe singleton access).
- //
- // Therefore, DO NOT USE THESE AS A GENERAL-PURPOSE SUBSTITUTE FOR DEFAULT
- // CONSTRUCTORS. There is only one case where you should use these: functions
- // which need to return a string by reference (e.g. as a class member
- // accessor), and don't have an empty string to use (e.g. in an error case).
- // These should not be used as initializers, function arguments, or return
- // values for functions which return by value or outparam.
- BUTIL_EXPORT const std::string& EmptyString();
- BUTIL_EXPORT const string16& EmptyString16();
- // Contains the set of characters representing whitespace in the corresponding
- // encoding. Null-terminated.
- BUTIL_EXPORT extern const wchar_t kWhitespaceWide[];
- BUTIL_EXPORT extern const char16 kWhitespaceUTF16[];
- BUTIL_EXPORT extern const char kWhitespaceASCII[];
- // Null-terminated string representing the UTF-8 byte order mark.
- BUTIL_EXPORT extern const char kUtf8ByteOrderMark[];
- // Removes characters in |remove_chars| from anywhere in |input|. Returns true
- // if any characters were removed. |remove_chars| must be null-terminated.
- // NOTE: Safe to use the same variable for both |input| and |output|.
- BUTIL_EXPORT bool RemoveChars(const string16& input,
- const butil::StringPiece16& remove_chars,
- string16* output);
- BUTIL_EXPORT bool RemoveChars(const std::string& input,
- const butil::StringPiece& remove_chars,
- std::string* output);
- // Replaces characters in |replace_chars| from anywhere in |input| with
- // |replace_with|. Each character in |replace_chars| will be replaced with
- // the |replace_with| string. Returns true if any characters were replaced.
- // |replace_chars| must be null-terminated.
- // NOTE: Safe to use the same variable for both |input| and |output|.
- BUTIL_EXPORT bool ReplaceChars(const string16& input,
- const butil::StringPiece16& replace_chars,
- const string16& replace_with,
- string16* output);
- BUTIL_EXPORT bool ReplaceChars(const std::string& input,
- const butil::StringPiece& replace_chars,
- const std::string& replace_with,
- std::string* output);
- // Removes characters in |trim_chars| from the beginning and end of |input|.
- // |trim_chars| must be null-terminated.
- // NOTE: Safe to use the same variable for both |input| and |output|.
- BUTIL_EXPORT bool TrimString(const string16& input,
- const butil::StringPiece16& trim_chars,
- string16* output);
- BUTIL_EXPORT bool TrimString(const std::string& input,
- const butil::StringPiece& trim_chars,
- std::string* output);
- // Truncates a string to the nearest UTF-8 character that will leave
- // the string less than or equal to the specified byte size.
- BUTIL_EXPORT void TruncateUTF8ToByteSize(const std::string& input,
- const size_t byte_size,
- std::string* output);
- // Trims any whitespace from either end of the input string. Returns where
- // whitespace was found.
- // The non-wide version has two functions:
- // * TrimWhitespaceASCII()
- // This function is for ASCII strings and only looks for ASCII whitespace;
- // Please choose the best one according to your usage.
- // NOTE: Safe to use the same variable for both input and output.
- enum TrimPositions {
- TRIM_NONE = 0,
- TRIM_LEADING = 1 << 0,
- TRIM_TRAILING = 1 << 1,
- TRIM_ALL = TRIM_LEADING | TRIM_TRAILING,
- };
- BUTIL_EXPORT TrimPositions TrimWhitespace(const string16& input,
- TrimPositions positions,
- butil::string16* output);
- BUTIL_EXPORT TrimPositions TrimWhitespace(const butil::StringPiece16& input,
- TrimPositions positions,
- butil::StringPiece16* output);
- BUTIL_EXPORT TrimPositions TrimWhitespaceASCII(const std::string& input,
- TrimPositions positions,
- std::string* output);
- BUTIL_EXPORT TrimPositions TrimWhitespaceASCII(const butil::StringPiece& input,
- TrimPositions positions,
- butil::StringPiece* output);
- // Deprecated. This function is only for backward compatibility and calls
- // TrimWhitespaceASCII().
- BUTIL_EXPORT TrimPositions TrimWhitespace(const std::string& input,
- TrimPositions positions,
- std::string* output);
- BUTIL_EXPORT TrimPositions TrimWhitespace(const butil::StringPiece& input,
- TrimPositions positions,
- butil::StringPiece* output);
- // Searches for CR or LF characters. Removes all contiguous whitespace
- // strings that contain them. This is useful when trying to deal with text
- // copied from terminals.
- // Returns |text|, with the following three transformations:
- // (1) Leading and trailing whitespace is trimmed.
- // (2) If |trim_sequences_with_line_breaks| is true, any other whitespace
- // sequences containing a CR or LF are trimmed.
- // (3) All other whitespace sequences are converted to single spaces.
- BUTIL_EXPORT string16 CollapseWhitespace(
- const string16& text,
- bool trim_sequences_with_line_breaks);
- BUTIL_EXPORT std::string CollapseWhitespaceASCII(
- const std::string& text,
- bool trim_sequences_with_line_breaks);
- // Returns true if |input| is empty or contains only characters found in
- // |characters|.
- BUTIL_EXPORT bool ContainsOnlyChars(const StringPiece& input,
- const StringPiece& characters);
- BUTIL_EXPORT bool ContainsOnlyChars(const StringPiece16& input,
- const StringPiece16& characters);
- // Returns true if the specified string matches the criteria. How can a wide
- // string be 8-bit or UTF8? It contains only characters that are < 256 (in the
- // first case) or characters that use only 8-bits and whose 8-bit
- // representation looks like a UTF-8 string (the second case).
- //
- // Note that IsStringUTF8 checks not only if the input is structurally
- // valid but also if it doesn't contain any non-character codepoint
- // (e.g. U+FFFE). It's done on purpose because all the existing callers want
- // to have the maximum 'discriminating' power from other encodings. If
- // there's a use case for just checking the structural validity, we have to
- // add a new function for that.
- BUTIL_EXPORT bool IsStringUTF8(const std::string& str);
- BUTIL_EXPORT bool IsStringUTF8(const StringPiece& str);
- BUTIL_EXPORT bool IsStringASCII(const StringPiece& str);
- BUTIL_EXPORT bool IsStringASCII(const string16& str);
- } // namespace butil
- #if defined(OS_WIN)
- #include "butil/strings/string_util_win.h"
- #elif defined(OS_POSIX)
- #include "butil/strings/string_util_posix.h"
- #else
- #error Define string operations appropriately for your platform
- #endif
- // Converts the elements of the given string. This version uses a pointer to
- // clearly differentiate it from the non-pointer variant.
- template <class str> inline void StringToLowerASCII(str* s) {
- for (typename str::iterator i = s->begin(); i != s->end(); ++i)
- *i = butil::ToLowerASCII(*i);
- }
- template <class str> inline str StringToLowerASCII(const str& s) {
- // for std::string and std::wstring
- str output(s);
- StringToLowerASCII(&output);
- return output;
- }
- // Converts the elements of the given string. This version uses a pointer to
- // clearly differentiate it from the non-pointer variant.
- template <class str> inline void StringToUpperASCII(str* s) {
- for (typename str::iterator i = s->begin(); i != s->end(); ++i)
- *i = butil::ToUpperASCII(*i);
- }
- template <class str> inline str StringToUpperASCII(const str& s) {
- // for std::string and std::wstring
- str output(s);
- StringToUpperASCII(&output);
- return output;
- }
- // Compare the lower-case form of the given string against the given ASCII
- // string. This is useful for doing checking if an input string matches some
- // token, and it is optimized to avoid intermediate string copies. This API is
- // borrowed from the equivalent APIs in Mozilla.
- BUTIL_EXPORT bool LowerCaseEqualsASCII(const std::string& a, const char* b);
- BUTIL_EXPORT bool LowerCaseEqualsASCII(const butil::string16& a, const char* b);
- // Same thing, but with string iterators instead.
- BUTIL_EXPORT bool LowerCaseEqualsASCII(std::string::const_iterator a_begin,
- std::string::const_iterator a_end,
- const char* b);
- BUTIL_EXPORT bool LowerCaseEqualsASCII(butil::string16::const_iterator a_begin,
- butil::string16::const_iterator a_end,
- const char* b);
- BUTIL_EXPORT bool LowerCaseEqualsASCII(const char* a_begin,
- const char* a_end,
- const char* b);
- BUTIL_EXPORT bool LowerCaseEqualsASCII(const butil::char16* a_begin,
- const butil::char16* a_end,
- const char* b);
- // Performs a case-sensitive string compare. The behavior is undefined if both
- // strings are not ASCII.
- BUTIL_EXPORT bool EqualsASCII(const butil::string16& a, const butil::StringPiece& b);
- // Returns true if str starts with search, or false otherwise.
- BUTIL_EXPORT bool StartsWithASCII(const std::string& str,
- const std::string& search,
- bool case_sensitive);
- BUTIL_EXPORT bool StartsWith(const butil::string16& str,
- const butil::string16& search,
- bool case_sensitive);
- // Returns true if str ends with search, or false otherwise.
- BUTIL_EXPORT bool EndsWith(const std::string& str,
- const std::string& search,
- bool case_sensitive);
- BUTIL_EXPORT bool EndsWith(const butil::string16& str,
- const butil::string16& search,
- bool case_sensitive);
- // Determines the type of ASCII character, independent of locale (the C
- // library versions will change based on locale).
- template <typename Char>
- inline bool IsAsciiWhitespace(Char c) {
- return c == ' ' || c == '\r' || c == '\n' || c == '\t';
- }
- template <typename Char>
- inline bool IsAsciiAlpha(Char c) {
- return ((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z'));
- }
- template <typename Char>
- inline bool IsAsciiDigit(Char c) {
- return c >= '0' && c <= '9';
- }
- template <typename Char>
- inline bool IsHexDigit(Char c) {
- return (c >= '0' && c <= '9') ||
- (c >= 'A' && c <= 'F') ||
- (c >= 'a' && c <= 'f');
- }
- template <typename Char>
- inline Char HexDigitToInt(Char c) {
- DCHECK(IsHexDigit(c));
- if (c >= '0' && c <= '9')
- return c - '0';
- if (c >= 'A' && c <= 'F')
- return c - 'A' + 10;
- if (c >= 'a' && c <= 'f')
- return c - 'a' + 10;
- return 0;
- }
- // Returns true if it's a whitespace character.
- inline bool IsWhitespace(wchar_t c) {
- return wcschr(butil::kWhitespaceWide, c) != NULL;
- }
- // Return a byte string in human-readable format with a unit suffix. Not
- // appropriate for use in any UI; use of FormatBytes and friends in ui/base is
- // highly recommended instead. TODO(avi): Figure out how to get callers to use
- // FormatBytes instead; remove this.
- BUTIL_EXPORT butil::string16 FormatBytesUnlocalized(int64_t bytes);
- // Starting at |start_offset| (usually 0), replace the first instance of
- // |find_this| with |replace_with|.
- BUTIL_EXPORT void ReplaceFirstSubstringAfterOffset(
- butil::string16* str,
- size_t start_offset,
- const butil::string16& find_this,
- const butil::string16& replace_with);
- BUTIL_EXPORT void ReplaceFirstSubstringAfterOffset(
- std::string* str,
- size_t start_offset,
- const std::string& find_this,
- const std::string& replace_with);
- // Starting at |start_offset| (usually 0), look through |str| and replace all
- // instances of |find_this| with |replace_with|.
- //
- // This does entire substrings; use std::replace in <algorithm> for single
- // characters, for example:
- // std::replace(str.begin(), str.end(), 'a', 'b');
- BUTIL_EXPORT void ReplaceSubstringsAfterOffset(
- butil::string16* str,
- size_t start_offset,
- const butil::string16& find_this,
- const butil::string16& replace_with);
- BUTIL_EXPORT void ReplaceSubstringsAfterOffset(std::string* str,
- size_t start_offset,
- const std::string& find_this,
- const std::string& replace_with);
- // Reserves enough memory in |str| to accommodate |length_with_null| characters,
- // sets the size of |str| to |length_with_null - 1| characters, and returns a
- // pointer to the underlying contiguous array of characters. This is typically
- // used when calling a function that writes results into a character array, but
- // the caller wants the data to be managed by a string-like object. It is
- // convenient in that is can be used inline in the call, and fast in that it
- // avoids copying the results of the call from a char* into a string.
- //
- // |length_with_null| must be at least 2, since otherwise the underlying string
- // would have size 0, and trying to access &((*str)[0]) in that case can result
- // in a number of problems.
- //
- // Internally, this takes linear time because the resize() call 0-fills the
- // underlying array for potentially all
- // (|length_with_null - 1| * sizeof(string_type::value_type)) bytes. Ideally we
- // could avoid this aspect of the resize() call, as we expect the caller to
- // immediately write over this memory, but there is no other way to set the size
- // of the string, and not doing that will mean people who access |str| rather
- // than str.c_str() will get back a string of whatever size |str| had on entry
- // to this function (probably 0).
- template <class string_type>
- inline typename string_type::value_type* WriteInto(string_type* str,
- size_t length_with_null) {
- DCHECK_GT(length_with_null, 1u);
- str->reserve(length_with_null);
- str->resize(length_with_null - 1);
- return &((*str)[0]);
- }
- //-----------------------------------------------------------------------------
- // Splits a string into its fields delimited by any of the characters in
- // |delimiters|. Each field is added to the |tokens| vector. Returns the
- // number of tokens found.
- BUTIL_EXPORT size_t Tokenize(const butil::string16& str,
- const butil::string16& delimiters,
- std::vector<butil::string16>* tokens);
- BUTIL_EXPORT size_t Tokenize(const std::string& str,
- const std::string& delimiters,
- std::vector<std::string>* tokens);
- BUTIL_EXPORT size_t Tokenize(const butil::StringPiece& str,
- const butil::StringPiece& delimiters,
- std::vector<butil::StringPiece>* tokens);
- // Does the opposite of SplitString().
- BUTIL_EXPORT butil::string16 JoinString(const std::vector<butil::string16>& parts,
- butil::char16 s);
- BUTIL_EXPORT std::string JoinString(
- const std::vector<std::string>& parts, char s);
- // Join |parts| using |separator|.
- BUTIL_EXPORT std::string JoinString(
- const std::vector<std::string>& parts,
- const std::string& separator);
- BUTIL_EXPORT butil::string16 JoinString(
- const std::vector<butil::string16>& parts,
- const butil::string16& separator);
- // Replace $1-$2-$3..$9 in the format string with |a|-|b|-|c|..|i| respectively.
- // Additionally, any number of consecutive '$' characters is replaced by that
- // number less one. Eg $$->$, $$$->$$, etc. The offsets parameter here can be
- // NULL. This only allows you to use up to nine replacements.
- BUTIL_EXPORT butil::string16 ReplaceStringPlaceholders(
- const butil::string16& format_string,
- const std::vector<butil::string16>& subst,
- std::vector<size_t>* offsets);
- BUTIL_EXPORT std::string ReplaceStringPlaceholders(
- const butil::StringPiece& format_string,
- const std::vector<std::string>& subst,
- std::vector<size_t>* offsets);
- // Single-string shortcut for ReplaceStringHolders. |offset| may be NULL.
- BUTIL_EXPORT butil::string16 ReplaceStringPlaceholders(
- const butil::string16& format_string,
- const butil::string16& a,
- size_t* offset);
- // Returns true if the string passed in matches the pattern. The pattern
- // string can contain wildcards like * and ?
- // The backslash character (\) is an escape character for * and ?
- // We limit the patterns to having a max of 16 * or ? characters.
- // ? matches 0 or 1 character, while * matches 0 or more characters.
- BUTIL_EXPORT bool MatchPattern(const butil::StringPiece& string,
- const butil::StringPiece& pattern);
- BUTIL_EXPORT bool MatchPattern(const butil::string16& string,
- const butil::string16& pattern);
- // Hack to convert any char-like type to its unsigned counterpart.
- // For example, it will convert char, signed char and unsigned char to unsigned
- // char.
- template<typename T>
- struct ToUnsigned {
- typedef T Unsigned;
- };
- template<>
- struct ToUnsigned<char> {
- typedef unsigned char Unsigned;
- };
- template<>
- struct ToUnsigned<signed char> {
- typedef unsigned char Unsigned;
- };
- template<>
- struct ToUnsigned<wchar_t> {
- #if defined(WCHAR_T_IS_UTF16)
- typedef unsigned short Unsigned;
- #elif defined(WCHAR_T_IS_UTF32)
- typedef uint32_t Unsigned;
- #endif
- };
- template<>
- struct ToUnsigned<short> {
- typedef unsigned short Unsigned;
- };
- #endif // BUTIL_STRINGS_STRING_UTIL_H_
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