TCL programming introduction (5)

TCL programming introduction (5)

Lsort-mode list List. -Mode:-ASCII -Dictionary is similar to acsii, but is case insensitive. -Convert integer to integer for comparison -Convert real to floating point and then compare -Command command: Execute Command for comparison. Open filename Open filename access   Open the file and return a file descriptor. Access R w a r + W + A +   The definition is the same as that in C. For example, if the first character of the file name is |, the file is opened in the form of a pipe. Set f [open | more W] Set f [open/etc/pass R] Proc name ARGs body   Create a new process to replace any existing process or command. Proc WF {file STR }{ Puts-nonewline $ file Str Flush $ File } Set f [open/tmp/a w] WF $ F "first line" WF $ F "second line"   Return can be used to return values at the end of the function. Puts-nonewline fileid string Write a string to the fileid. If-nonewline is not added, a linefeed is automatically generated. PWD Returns the current directory. Read fileid Read fileid numbytes   Read numbytes bytes from fileid. Regexp? Switches? Exp string? Matchvar? ? Submatchvar Submatchvar ...?   Execute Regular Expression matching. ? Switches? -Nocase is case insensitive. -Indices: return the matching interval.   For example: Regexp ^ ABC abcjsdfh // Return 1 Regexp ^ ABC abcjsdfh // Return 1 Puts $ // Return ABC Regexp-indices ^ ABC abcsdfjkhsdf // Return 1 Puts $ // Return "0 2" Regsub? Switchs? Exp string subspec varname Execute Regular Expression replacement and replace the part matching exp in string with the content of subspec. ? Switchs? -All replaces all matched parts. The first child is replaced by default, and the return value is the number of replicas. -Nocase is case insensitive. For example: Regsub ABC abcabcbac EEE B // Return 1 Puts $ B // Return "eeeabcabc" Regsub-all ABC abcabcabc EEE B // Return 3 Puts $ B // Return "eeeeeeeee" Return Return immediately from the current command. Proc FF {}{ Return Friday } Set a [ff] // A = "Friday" Scan string 'format "varname... Read the value from string to varname. Seek fileid offset? Origin? Move the file pointer. Origin: Start current end Offset starts from where it starts. Set varname? Value? Sets the value of varname or returns the value of varname. If not in a proc command, a global variable is generated. Source filename Read the content from filename and send it to TCL for explanation. Split string? Splitchars? Splits string into a list. The default Delimiter is blank. You can also use splitchars to set the delimiter. String subcommand arg... A string command. String compare string1 string2 Execute the string comparison in the C strcmp mode. Returns-1, 0, or 1. String first string1 string2 Find the location of the string2 definition appearance in string1. -1 is not found. String Length string Returns the length of a string. String Match pattern string Determine whether the string matches pattern. Pattern is given in the unified format of shell file names. String range string first last Returns the content from first to last in the string. String tolower string Converts string to lowercase. String toupper string Converts string to uppercase. String trim string Remove the Left and Right spaces of the string. String trimleft string Remove the left blank of string. String trimright string Remove the right white space of the string. Tell fileid Returns the file pointer position of the fileid. Time Command Run the command and calculate the time consumed. Time "ls -- color" Some file name 503 microseconds per Iteration Trace subcommand Trace subcommand arg...   Storage of monitoring variables. Many sub-commands are defined, but currently only Virable. Trace variable name Ops Command Name is the name of the variable. Ops is the operation to be monitored. R read W write U unset   The command that is executed when the command condition is met. The variable name when name1 name2 ops name1 is executed with three parameters. When name1 is a vector, name2 is a subscript, and OPS is the operation performed. For example: Proc FF {name1 name2 op }{ Puts [format "% S % s" name1 name2 op] } Set a hhh Trace variable a r {ff} Puts $ // Return "a r hhh" Unknown role name   Unknown is not part of TCL. When TCL finds an Unknown command, it will check whether there is an unknown command. If yes, it will be called and no error will occur. For example: #! /Usr/bin/tclsh Proc unknown {CWD ARGs }{ Puts $ CWD Puts $ ARGs } // The following is an error command Sdfdf SDF sdkhf sdjkfhkasdf jksdhfk // Return "sdfdf SDF sdkhf sdjkfhkasdf jksdhfk" Unset name... Delete one or more variables (scalar or vector ). Uplevel command... Connect the start parameter (as shown in Concat ). Finally, it is executed in the context specified by level. If level is an integer, the distance in the stack is given (it is to jump to another command environment for execution ). The default value is 1 (the upper layer ). For example: #! /Usr/bin/TCL Proc FF {}{ Set a "FF" // set local ------------------------- } Set a "global" FF Puts $ // Return "Global"   Next: #! /Usr/bin/TCL Proc FF {}{ Uplevel set a "FF" // change a in the upper-level Stack ------------------------------------- } Set a global FF Puts $ // Return "FF"   If level starts with # And returns an integer, level indicates the absolute position in the stack. For example, #0 indicates top-level ). A B C has three commands respectively. below is the call relationship between them, Top-level-> A-> B-> C-> uplevel level Absolute position: 0 1 2 3 When level is 1 or #2, it is executed in B's environment. 3 or #0 are all executed in the top-level environment. Upvar? Level? Othervar myvar? Othervar myvar ...? Set up connections for variables in different stacks. The level here is the same as the level in uplevel. For example: #! /Usr/bin/TCL Proc FF {name }{ Upvar $ name x Set X "FF" } Set a "global" FF Puts $ // Return "FF" While test body   For example: Set x 0 While {$ x <10 }{ Puts "X is $ X" Incr x }   The global variables under built-in variables of built-in variables are automatically managed by the Tcl library. It is generally read-only. Env Environment variable array. For example: Puts $ ENV (PATH) // Return/bin:/usr/x11r6/bin Errorcode   Some error messages are saved when an error occurs. Use the following format for storage: Childkilled PID signame msg Information when a signal is terminated. Childstatus PID code Format when a child program exits with a non-0 value. Childsusp PID signame msg Format when a subprogram is terminated due to a signal. None The error does not contain any additional information. UNIX errname msg The format used when a kernel call is incorrect. Errorinfo Contains information of one or more rows, and describes the program and information at which the error occurs.