upvar

Create link to variable in a different stack frame

也就是在不同的执行堆栈中创建一个指向其它堆栈变量的引用，语法格式为 upvar ?level? otherVar myVar ?otherVar myVar ...?，其中level默认为1，也就是指向它的调用者，也可以使用#0的方式指定绝对层级，otherVar是其它堆栈的变量，myVar是本地的变量，引用到了otherVar上，后续对myVar的修改都会反映到其它堆栈的otherVar上

TCL里面数组不能作为参数进行传递，我们可以使用upvar的特性引用数组。

set a 1proc test {} {# upvar 等级默认是1upvar a xputs "x: $x"set x 2# 注意这里的a是test内部的变量，不会影响到外部的a，反而是上面的x影响到了全局变量a，这就是upvar的作用set a 1
}# 这里的upvar a x 相当于 upvar 1 a x或者upvar #0 a x
# a是上一层的变量(也是全局变量), x是本地test作用域内的变量，引用到了全局变量a上，如果test里面对x进行了修改，a变量也会被修改
puts "org a: $a"
test
puts "aft a: $a"# -------------------------------------------------------------------------------------------------------------------proc test1 {p} {upvar 1 $p xputs $x
}proc test2 {} {set y "This is string."# 注意了，这里不能使用$y的方式传递参数了，那么这里就可以进行数组的传递，看下面的例子test1 y
}test2# -------------------------------------------------------------------------------------------------------------------proc test3 {a} {upvar $a maforeach n [array names ma] {puts "$n, $ma($n)"}
}proc test4 {} {set a(1) "11"set a(2) "22"test3 a
}test4# 上面执行的全部结果
# org a: 1
# x: 1
# aft a: 2
# This is string.
# 1, 11
# 2, 22

第一种情况:

第二种情况:

可以利用upvar传递数组参数，看下面的：

函数参数需要数组的情况

也就是不能直接使用数组作为参数
可以利用upvar命令:

利用upvar把函数参数转换为全局变量

proc test {x} {upvar #0 $x local #upvar #0表示在最顶层执行了命令set local 1
}test y  # y是以字符串的方式传递给了test这个函数puts $y # 虽然我们在任何地方都没有定义y这个变量，但是在函数test里面使用了upvar，这个y就变成了全局的变量了。

uplevel

假如：a函数调用了b函数，b函数调用了c函数。
如果c函数的某些步骤需要在b函数的作用域下执行，那么，可以在c函数里面，使用

uplevel 1 {#具体的tcl命令，可以跟多行
}#等同于
uplevel #2 {
}

也就是说，直接跟数字，是指定当前函数的前面几层，而#后面跟数字，表示的是绝对值是第几层，比如c下面指定uplevel 1表示的是c的上一层，也就是b，等同于uplevel #2，如果指定uplevel 2表示的是c的上一层的上一层，也就是a，等同于uplevel #1，可以使用info level命令查看当前的层级，如果不指定，默认是1

也就是在调用函数TC_222_Ixia_Join_Group1的时候，其实都是在它的调用者的作用域下执行了{}内的tcl内容，对应的如下：

函数a没有x这个变量，但是在调用b的时候，使用uplevel，定义了x变量，此时set x 1这个语句相当于在a里面执行的，所以后面的puts $x才可以正确的打印出1这个值

参考：tcl/tk参考——控制结构uplevel

clock

格式化输出时间

info

获取当前执行脚本

info script

获取当前执行脚本的路径

file normalize [info script]

获取当前执行层级

info level

string

string map

替换字符串内容:

string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc

注意原始字符串是没有改变的

问题：当string map {$a xyz} c ， 当 c，当 c，当a中有空格的时候的方法如下:

set a “a b”
string map {$a xyz} “123a b456” #这里由于{}括起来了，所以$a是一个字符串，没有被替换为a b，我们需要这样做：
set r \”$a\”\ xyz  #这里的r变量是一个字符串”a b” xyz
string map $r “123a b456” #这里其实就是string map ”a b” xyz “123a b456”了，满足要求

file

异常

catch {scripts} var
其中scripts是需要执行的脚本，var会存放scripts里面最后表达式的值，catch命令没有异常返回0，否则返回1

array

array set

array set var list

会创建一个数组var，后面跟定list，其中list的元素数量和必须是偶数，处于偶数的元素为key，偶数后一位为value
比如: array set a {x 1 y 2} 会创建出来$a(x)值是1，$a(y)值是2，如果后面的list长度不是偶数，会报错

array get

可以把一个数组转换为一个列表，相当于是array set的反向操作

parray

parray a

其实就是打印一个数组

regsub

regsub -all abc 123abc123 0 x 把123abc123里面的abc替换为0，并且把替换后的结果赋值给变量x

interp

proc a {} {puts a
}proc b {} {puts b
}proc c {} {interp alias {} a {} b
}c
a # 这里输出的是b

interp alias a_inter a b_inter b 意思是当调用a的时候，会使用b来代替，a_inter/b_inter表示不同的解释器，如果设定为{}表示当前解释器，也就是命令替换

exp_spawn

global

set a ""proc t {} {global a bset a 1set b 2puts "$a $b"
}t # 打印 1 2puts $a # 打印1
puts $b # 打印2 b并没有在全局空间定义，但是在函数t中定义了全局变量，所以这里可以直接使用

namespace

namespace eval

namespace eval some_xxx {expressions}

Activates a namespace called namespace and evaluates some code in that context. If the namespace does not already exist, it is created. If more than one arg argument is specified, the arguments are concatenated together with a space between each one in the same fashion as the eval command, and the result is evaluated.
If namespace has leading namespace qualifiers and any leading namespaces do not exist, they are automatically created.

namespace eval x {set a 1
}# puts $a # 这样使用会报错# 这样使用正确
puts $x::a namespace eval x {# 这里可以直接使用已有的puts $a
}namespace eval x::y {# puts $a # 这里不能直接使用set b 1
}namespace eval x {# puts $b # 这里也不能直接使用
}

namespace export

namespace eval ::test {namespace export init \connect \create
}

指定当前命名空间哪些命令可以使用

switch

set x 2switch $x {1 { # 如果匹配到了，则停止puts 1}2 -  # -表示不处理，会走到默认的default分支default {puts default}
}

TCL内部变量

auto_path: tcl找寻lib的位置，可以通过lappend的方法加入自己的lib库

The following global variables are created and managed automatically by the Tcl library. Except where noted below, these variables should normally be treated as read-only by application-specific code and by users.

env

This variable is maintained by Tcl as an array whose elements are the environment variables for the process. Reading an element will return the value of the corresponding environment variable. Setting an element of the array will modify the corresponding environment variable or create a new one if it does not already exist. Unsetting an element of env will remove the corresponding environment variable. Changes to the env array will affect the environment passed to children by commands like exec. If the entire env array is unset then Tcl will stop monitoring env accesses and will not update environment variables.
Under Windows, the environment variables PATH and COMSPEC in any capitalization are converted automatically to upper case. For instance, the PATH variable could be exported by the operating system as “path”, “Path”, “PaTh”, etc., causing otherwise simple Tcl code to have to support many special cases. All other environment variables inherited by Tcl are left unmodified. Setting an env array variable to blank is the same as unsetting it as this is the behavior of the underlying Windows OS. It should be noted that relying on an existing and empty environment variable will not work on Windows and is discouraged for cross-platform usage.

The following elements of env are special to Tcl:

env(HOME)

This environment variable, if set, gives the location of the directory considered to be the current user’s home directory, and to which a call of cd without arguments or with just “~” as an argument will change into. Most platforms set this correctly by default; it does not normally need to be set by user code.
env(TCL_LIBRARY)
If set, then it specifies the location of the directory containing library scripts (the value of this variable will be assigned to the tcl_library variable and therefore returned by the command info library). If this variable is not set then a default value is used.
Note that this environment variable should not normally be set.

env(TCLLIBPATH)

If set, then it must contain a valid Tcl list giving directories to search during auto-load operations. Directories must be specified in Tcl format, using “/” as the path separator, regardless of platform. This variable is only used when initializing the auto_path variable.
env(TCL_INTERP_DEBUG_FRAME)
If existing, it has the same effect as running interp debug {} -frame 1 as the very first command of each new Tcl interpreter.

errorCode

This variable holds the value of the -errorcode return option set by the most recent error that occurred in this interpreter. This list value represents additional information about the error in a form that is easy to process with programs. The first element of the list identifies a general class of errors, and determines the format of the rest of the list. The following formats for -errorcode return options are used by the Tcl core; individual applications may define additional formats.
ARITH code msg
This format is used when an arithmetic error occurs (e.g. an attempt to divide zero by zero in the expr command). Code identifies the precise error and msg provides a human-readable description of the error. Code will be either DIVZERO (for an attempt to divide by zero), DOMAIN (if an argument is outside the domain of a function, such as acos(-3)), IOVERFLOW (for integer overflow), OVERFLOW (for a floating-point overflow), or UNKNOWN (if the cause of the error cannot be determined).
Detection of these errors depends in part on the underlying hardware and system libraries.

CHILDKILLED pid sigName msg
This format is used when a child process has been killed because of a signal. The pid element will be the process’s identifier (in decimal). The sigName element will be the symbolic name of the signal that caused the process to terminate; it will be one of the names from the include file signal.h, such as SIGPIPE. The msg element will be a short human-readable message describing the signal, such as “write on pipe with no readers” for SIGPIPE.
CHILDSTATUS pid code
This format is used when a child process has exited with a non-zero exit status. The pid element will be the process’s identifier (in decimal) and the code element will be the exit code returned by the process (also in decimal).
CHILDSUSP pid sigName msg
This format is used when a child process has been suspended because of a signal. The pid element will be the process’s identifier, in decimal. The sigName element will be the symbolic name of the signal that caused the process to suspend; this will be one of the names from the include file signal.h, such as SIGTTIN. The msg element will be a short human-readable message describing the signal, such as “background tty read” for SIGTTIN.
NONE
This format is used for errors where no additional information is available for an error besides the message returned with the error. In these cases the -errorcode return option will consist of a list containing a single element whose contents are NONE.
POSIX errName msg
If the first element is POSIX, then the error occurred during a POSIX kernel call. The errName element will contain the symbolic name of the error that occurred, such as ENOENT; this will be one of the values defined in the include file errno.h. The msg element will be a human-readable message corresponding to errName, such as “no such file or directory” for the ENOENT case.
To set the -errorcode return option, applications should use library procedures such as Tcl_SetObjErrorCode, Tcl_SetReturnOptions, and Tcl_PosixError, or they may invoke the -errorcode option of the return command. If none of these methods for setting the error code has been used, the Tcl interpreter will reset the variable to NONE after the next error.

errorInfo

This variable holds the value of the -errorinfo return option set by the most recent error that occurred in this interpreter. This string value will contain one or more lines identifying the Tcl commands and procedures that were being executed when the most recent error occurred. Its contents take the form of a stack trace showing the various nested Tcl commands that had been invoked at the time of the error.

tcl_library

This variable holds the name of a directory containing the system library of Tcl scripts, such as those used for auto-loading. The value of this variable is returned by the info library command. See the library manual entry for details of the facilities provided by the Tcl script library. Normally each application or package will have its own application-specific script library in addition to the Tcl script library; each application should set a global variable with a name like $app_library (where app is the application’s name) to hold the network file name for that application’s library directory. The initial value of tcl_library is set when an interpreter is created by searching several different directories until one is found that contains an appropriate Tcl startup script. If the TCL_LIBRARY environment variable exists, then the directory it names is checked first. If TCL_LIBRARY is not set or doesn’t refer to an appropriate directory, then Tcl checks several other directories based on a compiled-in default location, the location of the binary containing the application, and the current working directory.

tcl_patchLevel

When an interpreter is created Tcl initializes this variable to hold a string giving the current patch level for Tcl, such as 8.4.16 for Tcl 8.4 with the first sixteen official patches, or 8.5b3 for the third beta release of Tcl 8.5. The value of this variable is returned by the info patchlevel command.

tcl_pkgPath

This variable holds a list of directories indicating where packages are normally installed. It is not used on Windows. It typically contains either one or two entries; if it contains two entries, the first is normally a directory for platform-dependent packages (e.g., shared library binaries) and the second is normally a directory for platform-independent packages (e.g., script files). Typically a package is installed as a subdirectory of one of the entries in $tcl_pkgPath. The directories in $tcl_pkgPath are included by default in the auto_path variable, so they and their immediate subdirectories are automatically searched for packages during package require commands. Note: tcl_pkgPath is not intended to be modified by the application. Its value is added to auto_path at startup; changes to tcl_pkgPath are not reflected in auto_path. If you want Tcl to search additional directories for packages you should add the names of those directories to auto_path, not tcl_pkgPath.

tcl_platform

This is an associative array whose elements contain information about the platform on which the application is running, such as the name of the operating system, its current release number, and the machine’s instruction set. The elements listed below will always be defined, but they may have empty strings as values if Tcl could not retrieve any relevant information. In addition, extensions and applications may add additional values to the array. The predefined elements are:

byteOrder

The native byte order of this machine: either littleEndian or bigEndian.

debug

If this variable exists, then the interpreter was compiled with and linked to a debug-enabled C run-time. This variable will only exist on Windows, so extension writers can specify which package to load depending on the C run-time library that is in use. This is not an indication that this core contains symbols.

engine

The name of the Tcl language implementation. When the interpreter is first created, this is always set to the string Tcl.

machine

The instruction set executed by this machine, such as intel, PPC, 68k, or sun4m. On UNIX machines, this is the value returned by uname -m.

os

The name of the operating system running on this machine, such as Windows 95, Windows NT, or SunOS. On UNIX machines, this is the value returned by uname -s. On Windows 95 and Windows 98, the value returned will be Windows 95 to provide better backwards compatibility to Windows 95; to distinguish between the two, check the osVersion.

osVersion

The version number for the operating system running on this machine. On UNIX machines, this is the value returned by uname -r. On Windows 95, the version will be 4.0; on Windows 98, the version will be 4.10.

platform

Either windows, or unix. This identifies the general operating environment of the machine.

threaded

If this variable exists, then the interpreter was compiled with threads enabled.

user

This identifies the current user based on the login information available on the platform. This value comes from the getuid() and getpwuid() system calls on Unix, and the value from the GetUserName() system call on Windows.

wordSize

This gives the size of the native-machine word in bytes (strictly, it is same as the result of evaluating sizeof(long) in C.)

pointerSize

This gives the size of the native-machine pointer in bytes (strictly, it is same as the result of evaluating sizeof(void*) in C.)

tcl_precision

This variable controls the number of digits to generate when converting floating-point values to strings. It defaults to 0. Applications should not change this value; it is provided for compatibility with legacy code.
The default value of 0 is special, meaning that Tcl should convert numbers using as few digits as possible while still distinguishing any floating point number from its nearest neighbours. It differs from using an arbitrarily high value for tcl_precision in that an inexact number like 1.4 will convert as 1.4 rather than 1.3999999999999999 even though the latter is nearer to the exact value of the binary number.
If tcl_precision is not zero, then when Tcl converts a floating point number, it creates a decimal representation of at most tcl_precision significant digits; the result may be shorter if the shorter result represents the original number exactly. If no result of at most tcl_precision digits is an exact representation of the original number, the one that is closest to the original number is chosen. If the original number lies precisely between two equally accurate decimal representations, then the one with an even value for the least significant digit is chosen; for instance, if tcl_precision is 3, then 0.3125 will convert to 0.312, not 0.313, while 0.6875 will convert to 0.688, not 0.687. Any string of trailing zeroes that remains is trimmed.
a tcl_precision value of 17 digits is “perfect” for IEEE floating-point in that it allows double-precision values to be converted to strings and back to binary with no loss of information. For this reason, you will often see it as a value in legacy code that must run on Tcl versions before 8.5. It is no longer recommended; as noted above, a zero value is the preferred method.
All interpreters in a thread share a single tcl_precision value: changing it in one interpreter will affect all other interpreters as well. Safe interpreters are not allowed to modify the variable.
Valid values for tcl_precision range from 0 to 17.

tcl_rcFileName

This variable is used during initialization to indicate the name of a user-specific startup file. If it is set by application-specific initialization, then the Tcl startup code will check for the existence of this file and source it if it exists. For example, for wish the variable is set to ~/.wishrc for Unix and ~/wishrc.tcl for Windows.

tcl_traceCompile

The value of this variable can be set to control how much tracing information is displayed during bytecode compilation. By default, tcl_traceCompile is zero and no information is displayed. Setting tcl_traceCompile to 1 generates a one-line summary in stdout whenever a procedure or top-level command is compiled. Setting it to 2 generates a detailed listing in stdout of the bytecode instructions emitted during every compilation. This variable is useful in tracking down suspected problems with the Tcl compiler.
This variable and functionality only exist if TCL_COMPILE_DEBUG was defined during Tcl’s compilation.

tcl_traceExec

The value of this variable can be set to control how much tracing information is displayed during bytecode execution. By default, tcl_traceExec is zero and no information is displayed. Setting tcl_traceExec to 1 generates a one-line trace in stdout on each call to a Tcl procedure. Setting it to 2 generates a line of output whenever any Tcl command is invoked that contains the name of the command and its arguments. Setting it to 3 produces a detailed trace showing the result of executing each bytecode instruction. Note that when tcl_traceExec is 2 or 3, commands such as set and incr that have been entirely replaced by a sequence of bytecode instructions are not shown. Setting this variable is useful in tracking down suspected problems with the bytecode compiler and interpreter.
This variable and functionality only exist if TCL_COMPILE_DEBUG was defined during Tcl’s compilation.

tcl_wordchars

The value of this variable is a regular expression that can be set to control what are considered “word” characters, for instances like selecting a word by double-clicking in text in Tk. It is platform dependent. On Windows, it defaults to \S, meaning anything but a Unicode space character. Otherwise it defaults to \w, which is any Unicode word character (number, letter, or underscore).

tcl_nonwordchars

The value of this variable is a regular expression that can be set to control what are considered “non-word” characters, for instances like selecting a word by double-clicking in text in Tk. It is platform dependent. On Windows, it defaults to \s, meaning any Unicode space character. Otherwise it defaults to \W, which is anything but a Unicode word character (number, letter, or underscore).

tcl_version

When an interpreter is created Tcl initializes this variable to hold the version number for this version of Tcl in the form x.y. Changes to x represent major changes with probable incompatibilities and changes to y represent small enhancements and bug fixes that retain backward compatibility. The value of this variable is returned by the info tclversion command.

argc

The number of arguments to tclsh or wish.

argv

Tcl list of arguments to tclsh or wish.

argv0

The script that tclsh or wish started executing (if it was specified) or otherwise the name by which tclsh or wish was invoked.

tcl_interactive

Contains 1 if tclsh or wish is running interactively (no script was specified and standard input is a terminal-like device), 0 otherwise.
The wish executable additionally specifies the following global variable:

geometry

If set, contains the user-supplied geometry specification to use for the main Tk window.

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