Returns 1 if command is a complete Tcl command in the sense of having no unclosed quotes, braces, brackets or array element names, If the command doesn't appear to be complete then 0 is returned. This command is typically used in line-oriented input environments to allow users to type in commands that span multiple lines; if the command isn't complete, the script can delay evaluating it until additional lines have been typed to complete the command.
RS: Could it be that info complete can be used generally to check whether a string can be parsed as a list? I used to use
expr {![catch {llength $x}]}for that purpose...
The answer: "no". It is possible for a string to be "info complete" but not be a list. To wit:
% set foo "{this is a test}{more stuff}"
{this is a test}{more stuff}
% llength $foo
list element in braces followed by "{more" instead of space
% info complete $foo
1AMG: It seems odd to me that [info complete] doesn't return false when its argument has a trailing backslash (or an odd number of trailing backslashes), since that's normally used to signify that the command is continued onto the next line. An interactive shell relying on [info complete] likely has to implement its own check for trailing backslashes, e.g.:
proc complete {script} {
expr {[info complete $script] && [regexp {(?:^|[^\\])(?:\\\\)*$} $script]}
}Example usage:
# single word
info complete a ;# 1
complete a ;# 1
# two words
info complete a\ b ;# 1
complete a\ b ;# 1
# unclosed quote
info complete \"a ;# 0
complete \"a ;# 0
# closed quote
info complete \"a\" ;# 0
complete \"a\" ;# 0
# unclosed brace
info complete \{a ;# 0
complete \{a ;# 0
# closed brace
info complete \{a\} ;# 1
complete \{a\} ;# 1
# unclosed nested brace
info complete \{\{a\} ;# 0
complete \{\{a\} ;# 0
# line ends in double backslash
info complete a\\\\ ;# 1
complete a\\\\ ;# 1
# line ends in single backslash
info complete a\\ ;# 1
complete a\\ ;# 0DKF: The key is that info complete in those cases sees a backslash at the end of a string which is OK, complete. It's when the backslash is followed by a newline that things are magically different:
puts [info complete "abc\\"] ;# 1 puts [info complete "abc\\\n"] ;# 0 puts [info complete "abc\\\ndef"] ;# 1 puts [info complete "abc\\\n "] ;# 1