Windows PowerShell command on Get-command Tcl

Manual Pages for UNIX Operating System command usage for man Tcl_SetObjLength

Tcl Library Procedures Tcl_StringObj(3TCL)

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NAME

Tcl_NewStringObj, Tcl_NewUnicodeObj, Tcl_SetStringObj,

Tcl_SetUnicodeObj, Tcl_GetStringFromObj, Tcl_GetString,

Tcl_GetUnicodeFromObj, Tcl_GetUnicode, Tcl_GetUniChar,

Tcl_GetCharLength, Tcl_GetRange, Tcl_AppendToObj,

Tcl_AppendUnicodeToObj, Tcl_AppendStringsToObj,

Tcl_AppendStringsToObjVA, Tcl_AppendObjToObj,

Tcl_SetObjLength, Tcl_ConcatObj, Tcl_AttemptSetObjLength -

manipulate Tcl objects as strings

SYNOPSIS

#include

Tcl_Obj *

Tcl_NewStringObj(bytes, length)

Tcl_Obj *

Tcl_NewUnicodeObj(unicode, numChars)

void

Tcl_SetStringObj(objPtr, bytes, length)

void

Tcl_SetUnicodeObj(objPtr, unicode, numChars)

char *

Tcl_GetStringFromObj(objPtr, lengthPtr)

char *

Tcl_GetString(objPtr)

Tcl_UniChar *

Tcl_GetUnicodeFromObj(objPtr, lengthPtr)

Tcl_UniChar *

Tcl_GetUnicode(objPtr)

Tcl_UniChar

Tcl_GetUniChar(objPtr, index)

int

Tcl_GetCharLength(objPtr)

Tcl_Obj *

Tcl_GetRange(objPtr, first, last)

void

Tcl_AppendToObj(objPtr, bytes, length)

void Tcl Last change: 8.1 1

Tcl Library Procedures Tcl_StringObj(3TCL)

Tcl_AppendUnicodeToObj(objPtr, unicode, numChars)

void

Tcl_AppendObjToObj(objPtr, appendObjPtr)

void

Tcl_AppendStringsToObj(objPtr, string, string, ... (char *) NULL)

void

Tcl_AppendStringsToObjVA(objPtr, argList)

void

Tcl_SetObjLength(objPtr, newLength)

int

Tcl_AttemptSetObjLength(objPtr, newLength)

Tcl_Obj *

Tcl_ConcatObj(objc, objv)

ARGUMENTS CONST char *bytes (in) Points to the | first byte of | an array of |

UTF-8-encoded |

contain embed- |

as the two- |

byte sequence | \700\600, use |

Tcl_ExternalToUtf|

to convert, or |

Tcl_NewByteArrayObj|

if the string |

is a collec- |

tion of unin- |

terpreted | bytes.) int length (in) The number of Tcl Last change: 8.1 2

Tcl Library Procedures Tcl_StringObj(3TCL)

bytes to copy from bytes

when initial-

izing, set-

ting, or appending to a string object. If negative, all bytes up to the first null are used.

CONST Tcl_UniChar *unicode (in) Points to the

first byte of an array of

Unicode char-

acters used to set or append to a string object. This byte array may

contain embed-

ded null char-

acters unless numChars is negative. int numChars (in) The number of

Unicode char-

acters to copy from unicode

when initial-

izing, set-

ting, or appending to a string object. If negative, all characters up to the first null character are used. int index (in) The index of the Unicode character to return. int first (in) The index of the first

Unicode char-

acter in the Tcl Last change: 8.1 3

Tcl Library Procedures Tcl_StringObj(3TCL)

Unicode range to be returned as a new object. int last (in) The index of the last

Unicode char-

acter in the Unicode range to be returned as a new object.

Tcl_Obj *objPtr (in/out) Points to an

object to manipulate.

Tcl_Obj *appendObjPtr (in) The object to

append to objPtr in

Tcl_AppendObjToObj.

int *lengthPtr (out) If non-NULL,

the location where

Tcl_GetStringFromObj

will store the the length of an object's string

representa-

tion.

CONST char *string (in) Null-

terminated string value to append to objPtr.

va_list argList (in) An argument

list which must have been initialised using

TCL_VARARGS_START,

and cleared

using va_end.

int newLength (in) New length for the string value of Tcl Last change: 8.1 4

Tcl Library Procedures Tcl_StringObj(3TCL)

objPtr, not including the final null character. int objc (in) The number of elements to concatenate.

Tcl_Obj *objv[] (in) The array of

objects to concatenate.

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DESCRIPTION

The procedures described in this manual entry allow Tcl objects to be manipulated as string values. They use the internal representation of the object to store additional information to make the string manipulations more efficient.

In particular, they make a series of append operations effi-

cient by allocating extra storage space for the string so that it doesn't have to be copied for each append. Also, indexing and length computations are optimized because the Unicode string representation is calculated and cached as

needed. When using the Tcl_Append* family of functions

where the interpreter's result is the object being appended

to, it is important to call Tcl_ResetResult first to ensure

you are not unintentionally appending to existing data in the result object.

Tcl_NewStringObj and Tcl_SetStringObj create a new object or

modify an existing object to hold a copy of the string given

by bytes and length. Tcl_NewUnicodeObj and

Tcl_SetUnicodeObj create a new object or modify an existing

object to hold a copy of the Unicode string given by unicode

and numChars. Tcl_NewStringObj and Tcl_NewUnicodeObj return

a pointer to a newly created object with reference count zero. All four procedures set the object to hold a copy of

the specified string. Tcl_SetStringObj and

Tcl_SetUnicodeObj free any old string representation as well

as any old internal representation of the object.

Tcl_GetStringFromObj and Tcl_GetString return an object's

string representation. This is given by the returned byte

pointer and (for Tcl_GetStringFromObj) length, which is

stored in lengthPtr if it is non-NULL. If the object's UTF

string representation is invalid (its byte pointer is NULL), the string representation is regenerated from the object's internal representation. The storage referenced by the returned byte pointer is owned by the object manager. It is passed back as a writable pointer so that extension author Tcl Last change: 8.1 5

Tcl Library Procedures Tcl_StringObj(3TCL)

creating their own Tcl_ObjType will be able to modify the

string representation within the Tcl_UpdateStringProc of

their Tcl_ObjType. Except for that limited purpose, the

pointer returned by Tcl_GetStringFromObj or Tcl_GetString

should be treated as read-only. It is recommended that this

pointer be assigned to a (CONST char *) variable. Even in the limited situations where writing to this pointer is

acceptable, one should take care to respect the copy-on-

write semantics required by Tcl_Obj's, with appropriate

calls to Tcl_IsShared and Tcl_DuplicateObj prior to any in-

place modification of the string representation. The pro-

cedure Tcl_GetString is used in the common case where the

caller does not need the length of the string representa-

tion.

Tcl_GetUnicodeFromObj and Tcl_GetUnicode return an object's

value as a Unicode string. This is given by the returned

pointer and (for Tcl_GetUnicodeFromObj) length, which is

stored in lengthPtr if it is non-NULL. The storage refer-

enced by the returned byte pointer is owned by the object

manager and should not be modified by the caller. The pro-

cedure Tcl_GetUnicode is used in the common case where the

caller does not need the length of the unicode string representation.

Tcl_GetUniChar returns the index'th character in the

object's Unicode representation.

Tcl_GetRange returns a newly created object comprised of the

characters between first and last (inclusive) in the object's Unicode representation. If the object's Unicode representation is invalid, the Unicode representation is regenerated from the object's string representation.

Tcl_GetCharLength returns the number of characters (as

opposed to bytes) in the string object.

Tcl_AppendToObj appends the data given by bytes and length

to the string representation of the object specified by objPtr. If the object has an invalid string representation, then an attempt is made to convert bytes is to the Unicode format. If the conversion is successful, then the converted

form of bytes is appended to the object's Unicode represen-

tation. Otherwise, the object's Unicode representation is invalidated and converted to the UTF format, and bytes is appended to the object's new string representation.

Tcl_AppendUnicodeToObj appends the Unicode string given by

unicode and numChars to the object specified by objPtr. If the object has an invalid Unicode representation, then unicode is converted to the UTF format and appended to the object's string representation. Appends are optimized to Tcl Last change: 8.1 6

Tcl Library Procedures Tcl_StringObj(3TCL)

handle repeated appends relatively efficiently (it overallo-

cates the string or Unicode space to avoid repeated reallo-

cations and copies of object's string value).

Tcl_AppendObjToObj is similar to Tcl_AppendToObj, but it

appends the string or Unicode value (whichever exists and is best suited to be appended to objPtr) of appendObjPtr to objPtr.

Tcl_AppendStringsToObj is similar to Tcl_AppendToObj except

that it can be passed more than one value to append and each

value must be a null-terminated string (i.e. none of the

values may contain internal null characters). Any number of string arguments may be provided, but the last argument must be a NULL pointer to indicate the end of the list.

Tcl_AppendStringsToObjVA is the same as

Tcl_AppendStringsToObj except that instead of taking a vari-

able number of arguments it takes an argument list.

The Tcl_SetObjLength procedure changes the length of the

string value of its objPtr argument. If the newLength argu-

ment is greater than the space allocated for the object's string, then the string space is reallocated and the old value is copied to the new space; the bytes between the old length of the string and the new length may have arbitrary values. If the newLength argument is less than the current

length of the object's string, with objPtr->length is

reduced without reallocating the string space; the original allocated size for the string is recorded in the object, so that the string length can be enlarged in a subsequent call

to Tcl_SetObjLength without reallocating storage. In all

cases Tcl_SetObjLength leaves a null character at objPtr-

>bytes[newLength].

Tcl_AttemptSetObjLength is identical in function to

Tcl_SetObjLength except that if sufficient memory to satisfy

the request cannot be allocated, it does not cause the Tcl interpreter to panic. Thus, if newLength is greater than the space allocated for the object's string, and there is not enough memory available to satisfy the request,

Tcl_AttemptSetObjLength will take no action and return 0 to

indicate failure. If there is enough memory to satisfy the

request, Tcl_AttemptSetObjLength behaves just like

Tcl_SetObjLength and returns 1 to indicate success.

The Tcl_ConcatObj function returns a new string object whose

value is the space-separated concatenation of the string

representations of all of the objects in the objv array.

Tcl_ConcatObj eliminates leading and trailing white space as

it copies the string representations of the objv array to the result. If an element of the objv array consists of Tcl Last change: 8.1 7

Tcl Library Procedures Tcl_StringObj(3TCL)

nothing but white space, then that object is ignored

entirely. This white-space removal was added to make the

output of the concat command cleaner-looking. Tcl_ConcatObj

returns a pointer to a newly-created object whose ref count

is zero.

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | runtime/tcl-8 |

|____________________|__________________|_

| Interface Stability| Uncommitted |

|____________________|_________________|

NOTES Source for Tcl is available on http://opensolaris.org. Tcl Last change: 8.1 8

Manual Pages for UNIX Operating System command usage for man Tcl_SetObjLength

NAME

Tcl_SetObjLength, Tcl_ConcatObj, Tcl_AttemptSetObjLength -

SYNOPSIS

Tcl_SetObjLength(objPtr, newLength)

DESCRIPTION

The Tcl_SetObjLength procedure changes the length of the

to Tcl_SetObjLength without reallocating storage. In all

cases Tcl_SetObjLength leaves a null character at objPtr-

Tcl_SetObjLength except that if sufficient memory to satisfy

Tcl_SetObjLength and returns 1 to indicate success.

SEE ALSO

ATTRIBUTES

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|