1info(n) Tcl Built-In Commands info(n)
2______________________________________________________________________________
6
8 info - Return information about the state of the Tcl interpreter
9
11 info option ?arg arg ...?
12_________________________________________________________________
13
16 This command provides information about various internals of the Tcl
17 interpreter. The legal options (which may be abbreviated) are:
18 info args procname
20 Returns a list containing the names of the arguments to proce‐
21 dure procname, in order. Procname must be the name of a Tcl
22 command procedure.
23 info body procname
25 Returns the body of procedure procname. Procname must be the
26 name of a Tcl command procedure.
27 info cmdcount
29 Returns a count of the total number of commands that have been
30 invoked in this interpreter.
31 info commands ?pattern?
33 If pattern is not specified, returns a list of names of all the │
34 Tcl commands visible (i.e. executable without using a qualified │
35 name) to the current namespace, including both the built-in com‐ │
36 mands written in C and the command procedures defined using the │
37 proc command. If pattern is specified, only those names match‐ │
38 ing pattern are returned. Matching is determined using the same │
39 rules as for string match. pattern can be a qualified name like │
40 Foo::print*. That is, it may specify a particular namespace │
41 using a sequence of namespace names separated by double colons │
42 (::), and may have pattern matching special characters at the │
43 end to specify a set of commands in that namespace. If pattern │
44 is a qualified name, the resulting list of command names has │
45 each one qualified with the name of the specified namespace, and │
46 only the commands defined in the named namespace are returned.
47 info complete command
49 Returns 1 if command is a complete Tcl command in the sense of
50 having no unclosed quotes, braces, brackets or array element
51 names. If the command does not appear to be complete then 0 is
52 returned. This command is typically used in line-oriented input
53 environments to allow users to type in commands that span multi‐
54 ple lines; if the command is not complete, the script can delay
55 evaluating it until additional lines have been typed to complete
56 the command.
57 info default procname arg varname
59 Procname must be the name of a Tcl command procedure and arg
60 must be the name of an argument to that procedure. If arg does
61 not have a default value then the command returns 0. Otherwise
62 it returns 1 and places the default value of arg into variable
63 varname.
64 info exists varName
66 Returns 1 if the variable named varName exists in the current
67 context (either as a global or local variable) and has been
68 defined by being given a value, returns 0 otherwise.
69 info frame ?number?
71 This command provides access to all frames on the stack, even
72 those hidden from info level. If number is not specified, this
73 command returns a number giving the frame level of the command.
74 This is 1 if the command is invoked at top-level. If number is
75 specified, then the result is a dictionary containing the loca‐
76 tion information for the command at the numbered level on the
77 stack.
78 If number is positive (> 0) then it selects a particular stack
80 level (1 refers to the top-most active command, i.e., info frame
81 itself, 2 to the command it was called from, and so on); other‐
82 wise it gives a level relative to the current command (0 refers
83 to the current command, i.e., info frame itself, -1 to its call‐
84 er, and so on).
85 This is similar to how info level works, except that this sub‐
87 command reports all frames, like sourced scripts, evals,
88 uplevels, etc.
89 Note that for nested commands, like “foo [bar [x]]”, only “x”
91 will be seen by an info frame invoked within “x”. This is the
92 same as for info level and error stack traces.
93 The result dictionary may contain the keys listed below, with
95 the specified meanings for their values:
96 type This entry is always present and describes the nature of
98 the location for the command. The recognized values are
99 source, proc, eval, and precompiled.
100 source
102 means that the command is found in a script loaded
103 by the source command.
104 proc
106 means that the command is found in dynamically
107 created procedure body.
108 eval
110 means that the command is executed by eval or
111 uplevel.
112 precompiled
114 means that the command is found in a precompiled
115 script (loadable by the package tbcload), and no
116 further information will be available.
117 line This entry provides the number of the line the command is
119 at inside of the script it is a part of. This information
120 is not present for type precompiled. For type source this
121 information is counted relative to the beginning of the
122 file, whereas for the last two types the line is counted
123 relative to the start of the script.
124 file This entry is present only for type source. It provides
126 the normalized path of the file the command is in.
127 cmd This entry provides the string representation of the com‐
129 mand. This is usually the unsubstituted form, however for
130 commands which are a pure list executed by eval it is the
131 substituted form as they have no other string representa‐
132 tion. Care is taken that the pure-List property of the
133 latter is not spoiled.
134 proc This entry is present only if the command is found in the
136 body of a regular Tcl procedure. It then provides the
137 name of that procedure.
138 lambda This entry is present only if the command is found in the
140 body of an anonymous Tcl procedure, i.e. a lambda. It
141 then provides the entire definition of the lambda in
142 question.
143 level This entry is present only if the queried frame has a
145 corresponding frame returned by info level. It provides
146 the index of this frame, relative to the current level (0
147 and negative numbers).
148 A thing of note is that for procedures statically defined in
150 files the locations of commands in their bodies will be reported
151 with type source and absolute line numbers, and not as type
152 proc. The same is true for procedures nested in statically
153 defined procedures, and literal eval scripts in files or stati‐
154 cally defined procedures.
155 In contrast, a procedure definition or eval within a dynamically
157 evaluated environment count linenumbers relative to the start of
158 their script, even if they would be able to count relative to
159 the start of the outer dynamic script. That type of number usu‐
160 ally makes more sense.
161 A different way of describing this behaviour is that file based
163 locations are tracked as deeply as possible, and where this is
164 not possible the lines are counted based on the smallest possi‐
165 ble eval or procedure body, as that scope is usually easier to
166 find than any dynamic outer scope.
167 The syntactic form {*} is handled like eval. I.e. if it is given
169 a literal list argument the system tracks the linenumber within
170 the list words as well, and otherwise all linenumbers are
171 counted relative to the start of each word (smallest scope)
172 info functions ?pattern?
174 If pattern is not specified, returns a list of all the math
175 functions currently defined. If pattern is specified, only
176 those functions whose name matches pattern are returned. Match‐
177 ing is determined using the same rules as for string match.
178 info globals ?pattern?
180 If pattern is not specified, returns a list of all the names of
181 currently-defined global variables. Global variables are vari‐
182 ables in the global namespace. If pattern is specified, only
183 those names matching pattern are returned. Matching is deter‐
184 mined using the same rules as for string match.
185 info hostname
187 Returns the name of the computer on which this invocation is
188 being executed. Note that this name is not guaranteed to be the
189 fully qualified domain name of the host. Where machines have
190 several different names (as is common on systems with both
191 TCP/IP (DNS) and NetBIOS-based networking installed,) it is the
192 name that is suitable for TCP/IP networking that is returned.
193 info level ?number?
195 If number is not specified, this command returns a number giving
196 the stack level of the invoking procedure, or 0 if the command
197 is invoked at top-level. If number is specified, then the
198 result is a list consisting of the name and arguments for the
199 procedure call at level number on the stack. If number is posi‐
200 tive then it selects a particular stack level (1 refers to the
201 top-most active procedure, 2 to the procedure it called, and so
202 on); otherwise it gives a level relative to the current level (0
203 refers to the current procedure, -1 to its caller, and so on).
204 See the uplevel command for more information on what stack lev‐
205 els mean.
206 info library
208 Returns the name of the library directory in which standard Tcl
209 scripts are stored. This is actually the value of the
210 tcl_library variable and may be changed by setting tcl_library.
211 See the tclvars manual entry for more information.
212 info loaded ?interp?
214 Returns a list describing all of the packages that have been
215 loaded into interp with the load command. Each list element is
216 a sub-list with two elements consisting of the name of the file
217 from which the package was loaded and the name of the package.
218 For statically-loaded packages the file name will be an empty
219 string. If interp is omitted then information is returned for
220 all packages loaded in any interpreter in the process. To get a
221 list of just the packages in the current interpreter, specify an
222 empty string for the interp argument.
223 info locals ?pattern?
225 If pattern is not specified, returns a list of all the names of
226 currently-defined local variables, including arguments to the
227 current procedure, if any. Variables defined with the global,
228 upvar and variable commands will not be returned. If pattern
229 is specified, only those names matching pattern are returned.
230 Matching is determined using the same rules as for string match.
231 info nameofexecutable
233 Returns the full path name of the binary file from which the
234 application was invoked. If Tcl was unable to identify the
235 file, then an empty string is returned.
236 info patchlevel
238 Returns the value of the global variable tcl_patchLevel; see the
239 tclvars manual entry for more information.
240 info procs ?pattern?
242 If pattern is not specified, returns a list of all the names of
243 Tcl command procedures in the current namespace. If pattern is
244 specified, only those procedure names in the current namespace
245 matching pattern are returned. Matching is determined using the
246 same rules as for string match. If pattern contains any names‐
247 pace separators, they are used to select a namespace relative to
248 the current namespace (or relative to the global namespace if
249 pattern starts with ::) to match within; the matching pattern is
250 taken to be the part after the last namespace separator.
251 info script ?filename?
253 If a Tcl script file is currently being evaluated (i.e. there is
254 a call to Tcl_EvalFile active or there is an active invocation
255 of the source command), then this command returns the name of
256 the innermost file being processed. If filename is specified,
257 then the return value of this command will be modified for the
258 duration of the active invocation to return that name. This is
259 useful in virtual file system applications. Otherwise the com‐
260 mand returns an empty string.
261 info sharedlibextension
263 Returns the extension used on this platform for the names of
264 files containing shared libraries (for example, .so under
265 Solaris). If shared libraries are not supported on this plat‐
266 form then an empty string is returned.
267 info tclversion
269 Returns the value of the global variable tcl_version; see the
270 tclvars manual entry for more information.
271 info vars ?pattern?
273 If pattern is not specified, returns a list of all the names of
274 currently-visible variables. This includes locals and cur‐
275 rently-visible globals. If pattern is specified, only those
276 names matching pattern are returned. Matching is determined
277 using the same rules as for string match. pattern can be a
278 qualified name like Foo::option*. That is, it may specify a
279 particular namespace using a sequence of namespace names sepa‐
280 rated by double colons (::), and may have pattern matching spe‐
281 cial characters at the end to specify a set of variables in that
282 namespace. If pattern is a qualified name, the resulting list
283 of variable names has each matching namespace variable qualified
284 with the name of its namespace. Note that a currently-visible
285 variable may not yet “exist” if it has not been set (e.g. a
286 variable declared but not set by variable).
287
289 This command prints out a procedure suitable for saving in a Tcl
290 script:
291 proc printProc {procName} {
293 set result [list proc $procName]
294 set formals {}
295 foreach var [info args $procName] {
296 if {[info default $procName $var def]} {
297 lappend formals [list $var $def]
298 } else {
299 # Still need the list-quoting because variable
300 # names may properly contain spaces.
301 lappend formals [list $var]
302 }
303 }
304 puts [lappend result $formals [info body $procName]]
305 }
306
308 global(n), proc(n)
309
311 command, information, interpreter, level, namespace, procedure, vari‐
312 able
313Tcl 8.4 info(n)