CkoFileAccess Objective-C Reference Documentation

CkoFileAccess

Current Version: 9.5.0.75

API for reading and writing files, creating and deleting directories, deleting directory trees, splitting and re-joining large files, etc. This is a freeware class. The reason for its existence is that in some programming languages, file I/O API's are limited or difficult to understand/use. This API provides an identical FILE I/O API across all programming languages supported by Chilkat.

Object Creation

CkoFileAccess *obj = [[CkoFileAccess alloc] init];

Properties

CurrentDir
@property (nonatomic, readonly, copy) NSString *CurrentDir;

The current working directory of the calling process.

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DebugLogFilePath
@property (nonatomic, copy) NSString *DebugLogFilePath;

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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EndOfFile
@property (nonatomic, readonly) BOOL EndOfFile;

Returns YES if the current open file is at the end-of-file.

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FileOpenError
@property (nonatomic, readonly, copy) NSNumber *FileOpenError;

This property is set by the following methods: FileOpen, OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend. It provides an error code indicating the failure reason. Possible values are:

  1. Success (No error)
  2. Access denied.
  3. File not found.
  4. General (non-specific) open error.
  5. File aleady exists.
  6. Path refers to a directory and the access requested involves writing.
  7. Too many symbolic links were encountered in resolving path.
  8. The process already has the maximum number of files open.
  9. Pathname is too long.
  10. The system limit on the total number of open files has been reached.
  11. Pathname refers to a device special file and no corresponding device exists.
  12. Insufficient kernel memory was available.
  13. Pathname was to be created but the device containing pathname has no room for the new file.
  14. A component used as a directory in pathname is not, in fact, a directory.
  15. Pathname refers to a regular file, too large to be opened (this would be a limitation of the underlying operating system, not a limitation imposed by Chilkat).
  16. Pathname refers to a file on a read-only filesystem and write access was requested.

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FileOpenErrorMsg
@property (nonatomic, readonly, copy) NSString *FileOpenErrorMsg;

The error message text associated with the FileOpenError code.

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LastErrorHtml
@property (nonatomic, readonly, copy) NSString *LastErrorHtml;

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
@property (nonatomic, readonly, copy) NSString *LastErrorText;

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
@property (nonatomic, readonly, copy) NSString *LastErrorXml;

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
@property (nonatomic) BOOL LastMethodSuccess;
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of YES indicates success, a value of NO indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = YES and failure = NO.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to YES. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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VerboseLogging
@property (nonatomic) BOOL VerboseLogging;

If set to YES, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is NO. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
@property (nonatomic, readonly, copy) NSString *Version;

Version of the component/library, such as "9.5.0.63"

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Methods

AppendAnsi
- (BOOL)AppendAnsi:(NSString *)text;

Appends a string using the ANSI character encoding to the currently open file.

Returns YES for success, NO for failure.

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AppendText
- (BOOL)AppendText:(NSString *)text
    charset:(NSString *)charset;

Appends a string using the character encoding specified by str to the currently open file.

Returns YES for success, NO for failure.

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AppendUnicodeBOM
- (BOOL)AppendUnicodeBOM;

Appends the 2-byte Unicode BOM (little endian) to the currently open file.

Returns YES for success, NO for failure.

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AppendUtf8BOM
- (BOOL)AppendUtf8BOM;

Appends the 3-byte utf-8 BOM to the currently open file.

Returns YES for success, NO for failure.

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DirAutoCreate
- (BOOL)DirAutoCreate:(NSString *)filePath;

Same as DirEnsureExists, except the argument is a file path (the last part of the path is a filename and not a directory). Creates all missing directories such that filePath may be created.

Returns YES for success, NO for failure.

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DirCreate
- (BOOL)DirCreate:(NSString *)path;

Creates a new directory specified by dirPath.

Returns YES for success, NO for failure.

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DirDelete
- (BOOL)DirDelete:(NSString *)path;

Deletes the directory specified by dirPath.

Returns YES for success, NO for failure.

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DirEnsureExists
- (BOOL)DirEnsureExists:(NSString *)dirPath;

Creates all directories necessary such that the entire dirPath exists.

Returns YES for success, NO for failure.

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FileClose
- (void)FileClose;

Closes the currently open file.

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FileContentsEqual
- (BOOL)FileContentsEqual:(NSString *)path1
    path2:(NSString *)path2;

Compares the contents of two files and returns YES if they are equal and otherwise returns NO. The actual contents of the files are only compared if the sizes are equal. The files are not entirely loaded into memory. Instead, they are compared chunk by chunk. This allows for any size files to be compared, regardless of the memory capacity of the computer.

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FileCopy
- (BOOL)FileCopy:(NSString *)existingPath
    newPath:(NSString *)newPath
    failIfExists:(BOOL)failIfExists;

Copys existingFilepath to newFilepath. If failIfExists is YES and newFilepath already exists, then an error is returned.

Returns YES for success, NO for failure.

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FileDelete
- (BOOL)FileDelete:(NSString *)path;

Deletes the file specified by filePath.

Returns YES for success, NO for failure.

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FileExists
- (BOOL)FileExists:(NSString *)path;

Returns YES if filePath exists, otherwise returns NO.

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FileExists3
- (NSNumber *)FileExists3:(NSString *)path;
Introduced in version 9.5.0.45

Returns 1 if the file exists, 0 if the file does not exist, and -1 if unable to check because of directory permissions or some other error that prevents the ability to obtain the information.

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FileOpen
- (BOOL)FileOpen:(NSString *)path
    accessMode:(NSNumber *)accessMode
    shareMode:(NSNumber *)shareMode
    createDisp:(NSNumber *)createDisp
    attr:(NSNumber *)attr;

This method should only be called on Windows operating systems. It's arguments are similar to the Windows Platform SDK function named CreateFile. For Linux, MAC OS X, and other operating system, use the OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend methods.

Opens a file for reading or writing. The arguments mirror the Windows CreateFile function:

Access Modes:
GENERIC_READ	(0x80000000)
GENERIC_WRITE (0x40000000)

Share Modes:
FILE_SHARE_READ(0x00000001)
FILE_SHARE_WRITE(0x00000002)

Create Dispositions
CREATE_NEW          1
CREATE_ALWAYS       2
OPEN_EXISTING       3
OPEN_ALWAYS         4
TRUNCATE_EXISTING   5

// Attributes:
FILE_ATTRIBUTE_READONLY         0x00000001
FILE_ATTRIBUTE_HIDDEN           0x00000002
FILE_ATTRIBUTE_SYSTEM           0x00000004
FILE_ATTRIBUTE_DIRECTORY        0x00000010
FILE_ATTRIBUTE_ARCHIVE          0x00000020
FILE_ATTRIBUTE_NORMAL           0x00000080
FILE_ATTRIBUTE_TEMPORARY	   0x00000100

Returns YES for success, NO for failure.

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FileRead
- (NSData *)FileRead:(NSNumber *)numBytes;

Reads bytes from the currently open file. maxNumBytes specifies the maximum number of bytes to read. Returns an empty byte array on error.

Returns nil on failure

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FileReadBd
- (BOOL)FileReadBd:(NSNumber *)maxNumBytes
    binData:(CkoBinData *)binData;
Introduced in version 9.5.0.64

Reads bytes from the currently open file. maxNumBytes specifies the maximum number of bytes to read. Appends the bytes to the binData.

Returns YES for success, NO for failure.

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FileRename
- (BOOL)FileRename:(NSString *)existingPath
    newPath:(NSString *)newPath;

Renames a file from existingFilepath to newFilepath.

Returns YES for success, NO for failure.

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FileSeek
- (BOOL)FileSeek:(NSNumber *)offset
    origin:(NSNumber *)origin;

Sets the file pointer for the currently open file. The offset is an offset in bytes from the origin. The origin can be one of the following:

0 = Offset is from beginning of file.
1 = Offset is from current position of file pointer.
2 = Offset is from the end-of-file (offset may be negative).

Returns YES for success, NO for failure.

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FileSize
- (NSNumber *)FileSize:(NSString *)path;

Returns the size, in bytes, of a file. Returns -1 for failure.

Returns YES for success, NO for failure.

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FileWrite
- (BOOL)FileWrite:(NSData *)data;

Writes bytes to the currently open file.

Returns YES for success, NO for failure.

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FileWriteBd
- (BOOL)FileWriteBd:(CkoBinData *)binData
    offset:(NSNumber *)offset
    numBytes:(NSNumber *)numBytes;
Introduced in version 9.5.0.64

Writes the contents of binData to the currently open file. To specify the entire contents of binData, set both offset and numBytes equal to 0. To write all remaining data starting at offset, then set numBytes equal to 0.

Returns YES for success, NO for failure.

More Information and Examples
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GenBlockId
- (NSString *)GenBlockId:(NSNumber *)index
    length:(NSNumber *)length
    encoding:(NSString *)encoding;
Introduced in version 9.5.0.58

This is purely a utility/convenience method -- initially created to help with block file uploads to Azure Blob storage. It generates a block ID string that is the decimal representation of the index in length chars, and then encoded according to encoding (which can be an encoding such as "base64", "hex", "ascii", etc.) For example, if index = 8, length = 12, and encoding = "base64", then the string "00000012" is returned base64 encoded.

Returns nil on failure

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GetDirectoryName
- (NSString *)GetDirectoryName:(NSString *)path;
Introduced in version 9.5.0.64

Returns the directory information for the specified path string.

GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir\'
GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir\') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir') returns 'C:\'
GetDirectoryName('C:\') returns 'C:\'

Returns nil on failure

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GetExtension
- (NSString *)GetExtension:(NSString *)path;
Introduced in version 9.5.0.64

Returns the extension of the specified path string.

GetExtension('C:\mydir.old\myfile.ext') returns '.ext'
GetExtension('C:\mydir.old\') returns ''

Returns nil on failure

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GetFileName
- (NSString *)GetFileName:(NSString *)path;
Introduced in version 9.5.0.64

Returns the file name and extension of the specified path string.

GetFileName('C:\mydir\myfile.ext') returns 'myfile.ext'
GetFileName('C:\mydir\') returns ''

Returns nil on failure

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GetFileNameWithoutExtension
- (NSString *)GetFileNameWithoutExtension:(NSString *)path;
Introduced in version 9.5.0.64

Returns the file name of the specified path string without the extension.

GetFileNameWithoutExtension('C:\mydir\myfile.ext') returns 'myfile'
GetFileNameWithoutExtension('C:\mydir\') returns ''

Returns nil on failure

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GetFileTime
- (CkoDateTime *)GetFileTime:(NSString *)path
    which:(NSNumber *)which;
Introduced in version 9.5.0.71

Gets one of the following date/times for a file:

0: Last-modified
1: Last-access
2: Creation
The "path" argument indicates which time to return. The values can be 0, 1, or 2.

Note: Linux filesystems do not keep a file's creation date/time. In such a case, this method will return the last-modified time.

Returns nil on failure

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GetLastModified
- (CkoDateTime *)GetLastModified:(NSString *)path;
Introduced in version 9.5.0.66

Gets the last-modified date/time for a file.

Returns nil on failure

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GetNumBlocks
- (NSNumber *)GetNumBlocks:(NSNumber *)blockSize;
Introduced in version 9.5.0.58

Returns the number of blocks in the currently open file. The number of bytes per block is specified by blockSize. The number of blocks is the file size divided by the blockSize, plus 1 if the file size is not evenly divisible by blockSize. For example, if the currently open file is 60500 bytes, and if the blockSize is 1000 bytes, then this method returns a count of 61 blocks.

Returns -1 if no file is open. Return 0 if the file is completely empty (0 bytes).

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GetTempFilename
- (NSString *)GetTempFilename:(NSString *)dirName
    prefix:(NSString *)prefix;

Creates a temporary filepath of the form dirPath\prefix_xxxx.TMP Where "xxxx" are random alpha-numeric chars. The returned filepath is guaranteed to not already exist.

Returns nil on failure

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OpenForAppend
- (BOOL)OpenForAppend:(NSString *)filePath;

Opens a file for appending. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten and the file pointer is positioned at the end of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns YES for success, NO for failure.

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OpenForRead
- (BOOL)OpenForRead:(NSString *)filePath;

Opens a file for reading. The file may contain any type of data (binary or text) and it must already exist. If the open failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns YES for success, NO for failure.

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OpenForReadWrite
- (BOOL)OpenForReadWrite:(NSString *)filePath;

Opens a file for reading/writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten, but the file pointer is positioned at the beginning of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns YES for success, NO for failure.

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OpenForWrite
- (BOOL)OpenForWrite:(NSString *)filePath;

Opens a file for writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will be overwritten. (For example, calling OpenForWrite on an existing file and then immediately closing the file will result in an empty file.) If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns YES for success, NO for failure.

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ReadBinaryToEncoded
- (NSString *)ReadBinaryToEncoded:(NSString *)path
    encoding:(NSString *)encoding;

Reads the entire contents of a binary file and returns it as an encoded string (using an encoding such as Base64, Hex, etc.) The encoding may be one of the following strings: base64, hex, qp, or url.

Returns nil on failure

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ReadBlock
- (NSData *)ReadBlock:(NSNumber *)blockIndex
    blockSize:(NSNumber *)blockSize;
Introduced in version 9.5.0.58

Reads the Nth block of a file, where the size of each block is specified by blockSize. The first block is at blockIndex 0. If the block to be read is the last in the file and there is not enough data to fill an entire block, then the partial block is returned.

Returns nil on failure

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ReadEntireFile
- (NSData *)ReadEntireFile:(NSString *)path;

Reads the entire contents of a binary file and returns the data.

Returns nil on failure

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ReadEntireTextFile
- (NSString *)ReadEntireTextFile:(NSString *)path
    charset:(NSString *)charset;

Reads the entire contents of a text file, interprets the bytes according to the character encoding specified by charset, and returns the text file as a string.

Returns nil on failure

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ReassembleFile
- (BOOL)ReassembleFile:(NSString *)partsDirPath
    partPrefix:(NSString *)partPrefix
    partExtension:(NSString *)partExtension
    reassembledFilename:(NSString *)reassembledFilename;

Reassembles a file previously split by the SplitFile method.

Returns YES for success, NO for failure.

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ReplaceStrings
- (NSNumber *)ReplaceStrings:(NSString *)path
    charset:(NSString *)charset
    existingString:(NSString *)existingString
    replacementString:(NSString *)replacementString;

Replaces all occurrences of existingString with replacementString in a file. The character encoding, such as utf-8, ansi, etc. is specified by charset.

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SaveLastError
- (BOOL)SaveLastError:(NSString *)path;

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns YES for success, NO for failure.

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SetCurrentDir
- (BOOL)SetCurrentDir:(NSString *)path;

Sets the current working directory for the calling process to dirPath.

Returns YES for success, NO for failure.

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SetFileTimes
- (BOOL)SetFileTimes:(NSString *)path
    create:(CkoDateTime *)create
    lastAccess:(CkoDateTime *)lastAccess
    lastModified:(CkoDateTime *)lastModified;

Sets the create date/time, the last-access date/time, and the last-modified date/time for a file. For non-Windows filesystems where create times are not implemented, the createTime is ignored.

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SetLastModified
- (BOOL)SetLastModified:(NSString *)path
    lastModified:(CkoDateTime *)lastModified;

Sets the last-modified date/time for a file.

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SplitFile
- (BOOL)SplitFile:(NSString *)fileToSplit
    partPrefix:(NSString *)partPrefix
    partExtension:(NSString *)partExtension
    partSize:(NSNumber *)partSize
    destDir:(NSString *)destDir;

Splits a file into chunks. Please refer to the example below:

Returns YES for success, NO for failure.

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TreeDelete
- (BOOL)TreeDelete:(NSString *)path;

Deletes an entire directory tree (all files and sub-directories).

Returns YES for success, NO for failure.

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WriteEntireFile
- (BOOL)WriteEntireFile:(NSString *)path
    fileData:(NSData *)fileData;

Opens/creates filePath, writes fileData, and closes the file.

Returns YES for success, NO for failure.

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WriteEntireTextFile
- (BOOL)WriteEntireTextFile:(NSString *)path
    fileData:(NSString *)fileData
    charset:(NSString *)charset
    includePreamble:(BOOL)includePreamble;

Opens filePath, writes textData using the character encoding specified by charset, and closes the file. If includedPreamble is YES and the charset is Unicode or utf-8, then the BOM is included at the beginning of the file.

Returns YES for success, NO for failure.

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