I am new to tcl, trying to learn, need a help for below.
My string looks like in configFileBuf and trying to replace second occurance of ConfENB:local-udp-port>31001" with XYZ, but below regsub cmd i was tried is always replacing with first occurance (37896). Plz help how to replace second occurance with xyz.
set ConfigFileBuf "<ConfENB:virtual-phy>
</ConfENB:local-ip-addr>
<ConfENB:local-udp-port>37896</ConfENB:local-udp-port>
</ConfENB:local-ip-addr>
<ConfENB:local-udp-port>31001</ConfENB:local-udp-port>
</ConfENB:virtual-phy>"
regsub -start 1 "</ConfENB:local-ip-addr>\[ \n\t\]+<ConfENB:local-udp-port>\[0-9 \]+</ConfENB:local-udp-port>" $ConfigFileBuf "XYZ" ConfigFileBuf
puts $ConfigFileBuf
You have to use regexp -indices to find where to start the replacement, and only then regsub. It's not too bad if you put the regular expression in its own variable.
set RE "</ConfENB:local-ip-addr>\[ \n\t\]+<ConfENB:local-udp-port>\[0-9 \]+</ConfENB:local-udp-port>"
set start [lindex [regexp -all -indices -inline $RE $ConfigFileBuf] 1 0]
regsub -start $start RE $ConfigFileBuf "XYZ" ConfigFileBuf
The 1 is the number of submatches in the RE (zero in this case) plus 1. You can compute it with the help of regexp -about, giving this piece of trickiness:
set RE "</ConfENB:local-ip-addr>\[ \n\t\]+<ConfENB:local-udp-port>\[0-9 \]+</ConfENB:local-udp-port>"
set relen [expr {1 + [lindex [regexp -about $RE] 0]}]
set start [lindex [regexp -all -indices -inline $RE $ConfigFileBuf] $relen 0]
regsub -start $start RE $ConfigFileBuf "XYZ" ConfigFileBuf
If your string was well-formed XML I'd suggest something like tDOM to manipulate it. DOM-style manipulation is almost always better than regular expression-based manipulation on XML markup. (I mention this on the off chance that it's actually supposed to be XML and you just quoted it wrong.)
It looks like you're trying to use -start 1 to tell regsub to skip the first match. The starting index is actually a character index, so in this invocation regsub will just skip the first character in the string. You could set -start further into your string, but that's fragile unless you use regexp to calculate where the first match ends.
I think the best solution would be to get a list of indices to matches by invoking regexp with -all -inline -indices, pick out the second index pair using lindex and finally use string replace to perform the substitution, like this:
set pattern {</ConfENB:local-ip-addr>[ \n\t]+<ConfENB:local-udp-port>[0-9 ]+</ConfENB:local-udp-port>}
set matches [regexp -all -inline -indices -- $pattern $ConfigFileBuf]
set match [lindex $matches 1]
set ConfigFileBuf [string replace $ConfigFileBuf {*}$match XYZ]
The variable match contains a pair of indices (start and end, respectively) for the range of characters you want to replace. As string replace expects those indices to be in different arguments you need to expand $match with the {*} prefix. If you have an earlier version of Tcl than 8.5, you need a slight change to the above code:
foreach {start end} $match break
set ConfigFileBuf [string replace $ConfigFileBuf $start $end XYZ]
In passing, note that you can avoid escaping e.g. character sets in a regular expression if you quote it with braces instead of double quotes.
Documentation links: regexp, lindex, string
Related
I have a list and need to search some strings in this list. My list is like following:
list1 = {slt0_reg_11.CK slt0_reg_11.Q slt0_reg_12.CK slt0_reg_12.Q}
I am trying to use lsearch to check if above list includes some strings or not. Strings are like:
string1 = {slt0_reg_1 slt0_reg_1}
I am doing the following to check this:
set listInd [lsearch -all -exact -nocase -regexp $list1 $string1]
This commands gives the indexes if list1 includes $string1 (This is what I want). However, problem is if I have a string like slt0_reg_1, the above command identifies the first two elements of the list (slt0_reg_11.CK slt0_reg_11.Q) because these covers the string I search.
How can I make exact search?
It sound like you want to add in word-boundary constraints (\y) to your RE. (Don't use -exact and -regexp at the same time; only one of those modes can be used on any run because they change the comparison engine used.) A little care must be taken because we can't enclose the RE in braces as we want to do variable substitution within it.
set list1 {slt0_reg_11.CK slt0_reg_11.Q slt0_reg_12.CK slt0_reg_12.Q}
foreach str {slt0_reg_11 slt0_reg_1} {
set matches [lsearch -all -regexp $list1 "\\y$str\\y"]
puts "$str: $matches"
}
Prints:
slt0_reg_11: 0 1
slt0_reg_1:
If you want to compare your list for an exact match of the part before the dot against another list, you may be better off using lmap:
set index -1
set listInd [lmap str $list1 {
incr index
if {[lindex [split $str .] 0] ni $string1} continue
set index
}]
I have the below line:
^ 1 0.02199 0.03188 0.03667 0.00136 0.04155 0.00000 1.07223 1.07223 -0.47462 0.00335 -0.46457 buf_63733/Z DCKBD1BWP240H11P57PDULVT -
I want to replace column 3 with a different value and to keep the entire line with spaces as is.
I tried lreplace - but spaces deleted.
string map can only replace a word but didn't find a way to replace exact column.
Can someone advice?
Assuming the columns are separated by at least 2 spaces, you could use something like:
set indices [regexp -all -indices -inline {\S+(?:\s\S+)?\s{2,}} $line]
set colCount 1
set newValue 0.01234
foreach pair $indices {
if {$colCount == 3} {
lassign $pair start end
set column [string range $line $start $end]
set value [string trimright $column]
set valueEnd [expr {$end-[string length $column]+[string length $value]}]
set newLine [string replace $line $start $valueEnd $newValue]
} elseif {$colCount > 3} {
break
}
incr colCount
}
You can change the newValue to something else or the newLine to line if you don't need the old line.
Another method uses regsub to inject a command into the replacement string, and then subst to evaluate it. This is like perl's s/pattern/code/e
set newline [subst [regsub {^((?:\s+\S+){2})(\s+\S+)} $line \
{\1[format "%*s" [string length "\2"] $newvalue]}]]
I have a string abc.def.ghi.j and I want to remove abc. from that, so that I have def.ghi.j.
1) What would be the best approach to remove such a prefix which has a specific pattern?
2) Since in this case, abc is coincidentally the prefix, that probably makes things easier. What if we wanted abc.ghi.j as the output?
I tried it with the split method like this
set name abc.def.ghi.j
set splitVar [split $name {{abc.}} ]
The problem is that it splits across each of a, b, c and . seperately instead of as a whole.
Well, there's a few ways, but the main ones are using string replace, regsub, string map, or split-lreplace-join.
We probably ought to be a bit careful because we must first check if the prefix really is a prefix. Fortunately, string equal has a -length operation that makes that easy:
if {[string equal -length [string length $prefix] $prefix $string]} {
# Do the replacement
}
Personally, I'd probably use regsub but then I'm happy with using RE engine tricks.
Using string replace
set string [string replace $string 0 [string length $prefix]-1]
# Older versions require this instead:
# set string [string replace $string 0 [expr {[string length $prefix]-1}]]
Using regsub
# ***= is magical and says "rest of RE is simple plain text, no escapes"
regsub ***=$prefix $string "" string
Using string map
# Requires cunning to anchor to the front; \uffff is unlikely in any real string
set string [string map [list \uffff$prefix ""] \uffff$string]
Using split…join
This is about what you were trying to do. It depends on the . being a sort of separator.
set string [join [lrange [split $string "."] 1 end] "."]
I have a string in this pattern:
2(some_substring) -> 3(some_other_substring)
Now these number can be anything.
I think this answer would solve the problem. But it gives all the integers in one variable. I want them to be in different variables, so that I can analyze them. Can we split it? But Splitting would cause problem:
If the the numbers are not single-digit, then the splitting will be erroneous.
Is there any other way?
You can use a variation of this: instead of removing the non-digit characters, you can extract all digit characters into a list:
set text {2(some_substring) -> 3(some_other_substring)}
set numbers [regexp -all -inline -- {[0-9]+} $text]
puts $numbers
# => 2 3
And to get each number, you can use lindex:
puts [lindex $numbers 0]
# => 2
Or in versions 8.5 and later, you can use lassign to assign them to specific variable names:
lassign $numbers first second
puts $first
# => 2
puts $second
# => 3
In regexp -all -inline -- {[0-9]+} $text, -all extract all the matches, -inline puts the matches into a list, -- ends the options, [0-9]+ matches at least one integer.
To extend Jerry's answer, in case digits can appear within the parentheses, a regular expression to only extract digits that are immediately followed by an open parenthesis is: {\d+(=\()}
% set text {2(some_6substring) -> 3(some_other_5substring)}
2(some_6substring) -> 3(some_other_5substring)
% lassign [regexp -all -inline {\d+(?=\()} $text] first second
% set first
2
% set second
3
This assumes that you don't have nested parentheses.
I am trying to write a Tcl script in which I need to match a variable in a regular expression.
For instance, file has some lines of code containing 'major'. Out of all these lines I need to identify one particular line:
major("major",0x32)
I m using variable p1 for 'major' (set p1 major)
How can I write a regexp using variable p1 ($p1) to capture that particular line?
regexp -- "$p1\\(\"$p1\",0x32\\)" $line match
In tclsh:
% set line {major("major",0x32)}
major("major",0x32)
% set p1 major
major
% regexp -- "$p1\\(\"$p1\",0x32\\)" $line match
1
% puts $match
major("major",0x32)
Use a String Match
If you just want to know whether a single line matches, you can test for string match rather than a regular expression. This is often faster and less finicky. For example:
set fh [open /tmp/foo]
set lines [read $fh]
close $fh
set p1 major
set lines [split $lines "\n"]
foreach line $lines {
if {[string match *$p1* $line]} {set match $line}
}
puts $match
Note that this will store the entire line in match, and not just the search pattern. This is probably what you want, but your mileage may vary.