CODEWITHSUNDEEP
tcl
user2045143
user2045143

Reputation: 249

How to deal with lindex and backslashes in TCL?

I have a bunch of data I am parsing through Tcl but running into issues when using lindex on the strings since it contains backslashes.

For example, 

$data is a list split by lines, 
{123 somethinghere/somethingthere/\idontcare 123ff}
{456 apples/oranges/\bananas 921} 
{999 pikachu/ratata/\snorlax ftp}

I loop on $data and use lindex to split this data and group it according to its type:

foreach item $data {
    set num [lindex $item 0]
    set paths [lindex $item 1]
    set output [lindex $item 2]
}

Unfortunately, the backslashes escape the text I want. 

puts "$paths"
somethinghere/somethingthere/dontcare

Ideally I don't even want to preserve the backslashes. My preferred data on $path would be:

puts "$paths"
somethinghere/somethingthere/idontcare

Suggestions? I don't want to use regexp unless that's the only way.

Upvotes: 5

Views: 663

Answers (1)

slebetman
slebetman

Reputation: 113906

First rule of lists is: don't treat non-list things as lists (well, there are exceptions to this but your data is a good example why you should follow the rule in 99% of cases).

To convert the string properly to a list use split:

set i [split $item " "]

If the split character is variable or is more than one char use regexp:

set i [regexp -inline -all {\S+} $item]

By using commands that return lists you are guaranteed that you get a proper list. Unless you're 100% sure (the exception) strings are not always parseable as lists.

Now, as for how to get rid of \. You can of course use regexp for this:

set item [regsub -all {\\} $item]

But there's a better way to do this without using regexp (which I'm sure you'd appreciate), use string map:

set item [string map {"\\" ""} $item]

Upvotes: 7

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