如何仅替换TCL regexp中的前n个匹配实例？

我需要将前50个

abc

替换为

bcd

。我试过下面的方法，但不起作用

set a "1 abc 2 abc 3 abc 4 abc......... 100 abc"
regsub -all "(.*?(abc).*)(50)" $a "bcd \1" b
puts $b

字符串中的数字用于演示。字符串可以是任意的：

set a "hh abc cc abc hh abc cc abc dd abc hh abc......... hh abc"

---

您可以使用此自定义过程，该过程使用替换函数：

set a "1 abc 2 abc 3 abc 4 abc......... 100 abc"

proc rangeSub {a first last string sub} {
  # This variable keeps the count of matches
  set count 0
  proc re_sub {str first last rep} {
    upvar count count
    incr count
    # If match number within wanted range, replace with rep, else return original string
    if {$count >= $first && $count <= $last} {
      return $rep
    } else {
      return $str
    }
  }

  set cmd {[re_sub "\0" $first $last $sub]}
  set b [subst [regsub -all "\\y$string\\y" $a $cmd]]

  return $b
}

# Here replacing the 1st to 3rd occurrences of abc
puts [rangeSub $a 1 3 "abc" "bcd"]
# => 1 bcd 2 bcd 3 bcd 4 abc......... 100 abc
puts [rangeSub $a 2 3 "abc" "bcd"]
# => 1 abc 2 bcd 3 bcd 4 abc......... 100 abc

---

您可以使用此自定义过程，该过程使用替换函数：

set a "1 abc 2 abc 3 abc 4 abc......... 100 abc"

proc rangeSub {a first last string sub} {
  # This variable keeps the count of matches
  set count 0
  proc re_sub {str first last rep} {
    upvar count count
    incr count
    # If match number within wanted range, replace with rep, else return original string
    if {$count >= $first && $count <= $last} {
      return $rep
    } else {
      return $str
    }
  }

  set cmd {[re_sub "\0" $first $last $sub]}
  set b [subst [regsub -all "\\y$string\\y" $a $cmd]]

  return $b
}

# Here replacing the 1st to 3rd occurrences of abc
puts [rangeSub $a 1 3 "abc" "bcd"]
# => 1 bcd 2 bcd 3 bcd 4 abc......... 100 abc
puts [rangeSub $a 2 3 "abc" "bcd"]
# => 1 abc 2 bcd 3 bcd 4 abc......... 100 abc

---

我希望这可以通过同时使用

regexp

和

regsub

来实现

%
% set count 0
0
% # Don't bother about this 'for' loop. It is just for input generation
% for { set i 65} {$i < 123} {incr i} {
        if {$count == 101} break
        if { $i >= 90 && $i <=96} {
                continue
        }
        for { set j 65 } {$j < 123} {incr j} {
                if {$count == 101} break
                if { $j >= 90 && $j <=96} {
                        continue
                }
                incr count
                append input "[format %c%c $i $j] abc "


        }
}
%
% # Following the 'input' value taken for processing
% # So, concentrate only from now on wards :D
% set input
AA abc AB abc AC abc AD abc AE abc AF abc AG abc AH abc AI abc AJ abc AK abc AL abc AM abc AN abc AO abc AP abc AQ abc AR abc AS abc AT abc AU abc AV abc AW abc AX abc AY abc Aa abc Ab abc Ac abc Ad abc Ae abc Af abc Ag abc Ah abc Ai abc Aj abc Ak abc Al abc Am abc An abc Ao abc Ap abc Aq abc Ar abc As abc At abc Au abc Av abc Aw abc Ax abc Ay abc Az abc BA abc BB abc BC abc BD abc BE abc BF abc BG abc BH abc BI abc BJ abc BK abc BL abc BM abc BN abc BO abc BP abc BQ abc BR abc BS abc BT abc BU abc BV abc BW abc BX abc BY abc Ba abc Bb abc Bc abc Bd abc Be abc Bf abc Bg abc Bh abc Bi abc Bj abc Bk abc Bl abc Bm abc Bn abc Bo abc Bp abc Bq abc Br abc Bs abc Bt abc Bu abc Bv abc Bw abc Bx abc By abc
%
% regexp "(.*?abc.*?){50}" $input match; #First matching upto '50' occurence
1
% regsub -all "((.*?)abc.*?)" $match "\\2bcd" replaceText; #Replacing the 'abc' with 'bcd'
50
% set replaceText
% regsub $match $input $replaceText output; #At last, replace this content from the main input
1
% 
% set output
AA bcd AB bcd AC bcd AD bcd AE bcd AF bcd AG bcd AH bcd AI bcd AJ bcd AK bcd AL bcd AM bcd AN bcd AO bcd AP bcd AQ bcd AR bcd AS bcd AT bcd AU bcd AV bcd AW bcd AX bcd AY bcd Aa bcd Ab bcd Ac bcd Ad bcd Ae bcd Af bcd Ag bcd Ah bcd Ai bcd Aj bcd Ak bcd Al bcd Am bcd An bcd Ao bcd Ap bcd Aq bcd Ar bcd As bcd At bcd Au bcd Av bcd Aw bcd Ax bcd Ay bcd Az abc BA abc BB abc BC abc BD abc BE abc BF abc BG abc BH abc BI abc BJ abc BK abc BL abc BM abc BN abc BO abc BP abc BQ abc BR abc BS abc BT abc BU abc BV abc BW abc BX abc BY abc Ba abc Bb abc Bc abc Bd abc Be abc Bf abc Bg abc Bh abc Bi abc Bj abc Bk abc Bl abc Bm abc Bn abc Bo abc Bp abc Bq abc Br abc Bs abc Bt abc Bu abc Bv abc Bw abc Bx abc By abc

%
%设置计数0
0
%#不要为这个“for”循环操心。它只是用于生成输入
%对于{set i 65}{$i<123}{incr i}{
如果{$count==101}中断
如果{$i>=90&&$i=90&&$j我希望这可以通过同时使用
regexp
和
regsub
来实现

%
% set count 0
0
% # Don't bother about this 'for' loop. It is just for input generation
% for { set i 65} {$i < 123} {incr i} {
        if {$count == 101} break
        if { $i >= 90 && $i <=96} {
                continue
        }
        for { set j 65 } {$j < 123} {incr j} {
                if {$count == 101} break
                if { $j >= 90 && $j <=96} {
                        continue
                }
                incr count
                append input "[format %c%c $i $j] abc "


        }
}
%
% # Following the 'input' value taken for processing
% # So, concentrate only from now on wards :D
% set input
AA abc AB abc AC abc AD abc AE abc AF abc AG abc AH abc AI abc AJ abc AK abc AL abc AM abc AN abc AO abc AP abc AQ abc AR abc AS abc AT abc AU abc AV abc AW abc AX abc AY abc Aa abc Ab abc Ac abc Ad abc Ae abc Af abc Ag abc Ah abc Ai abc Aj abc Ak abc Al abc Am abc An abc Ao abc Ap abc Aq abc Ar abc As abc At abc Au abc Av abc Aw abc Ax abc Ay abc Az abc BA abc BB abc BC abc BD abc BE abc BF abc BG abc BH abc BI abc BJ abc BK abc BL abc BM abc BN abc BO abc BP abc BQ abc BR abc BS abc BT abc BU abc BV abc BW abc BX abc BY abc Ba abc Bb abc Bc abc Bd abc Be abc Bf abc Bg abc Bh abc Bi abc Bj abc Bk abc Bl abc Bm abc Bn abc Bo abc Bp abc Bq abc Br abc Bs abc Bt abc Bu abc Bv abc Bw abc Bx abc By abc
%
% regexp "(.*?abc.*?){50}" $input match; #First matching upto '50' occurence
1
% regsub -all "((.*?)abc.*?)" $match "\\2bcd" replaceText; #Replacing the 'abc' with 'bcd'
50
% set replaceText
% regsub $match $input $replaceText output; #At last, replace this content from the main input
1
% 
% set output
AA bcd AB bcd AC bcd AD bcd AE bcd AF bcd AG bcd AH bcd AI bcd AJ bcd AK bcd AL bcd AM bcd AN bcd AO bcd AP bcd AQ bcd AR bcd AS bcd AT bcd AU bcd AV bcd AW bcd AX bcd AY bcd Aa bcd Ab bcd Ac bcd Ad bcd Ae bcd Af bcd Ag bcd Ah bcd Ai bcd Aj bcd Ak bcd Al bcd Am bcd An bcd Ao bcd Ap bcd Aq bcd Ar bcd As bcd At bcd Au bcd Av bcd Aw bcd Ax bcd Ay bcd Az abc BA abc BB abc BC abc BD abc BE abc BF abc BG abc BH abc BI abc BJ abc BK abc BL abc BM abc BN abc BO abc BP abc BQ abc BR abc BS abc BT abc BU abc BV abc BW abc BX abc BY abc Ba abc Bb abc Bc abc Bd abc Be abc Bf abc Bg abc Bh abc Bi abc Bj abc Bk abc Bl abc Bm abc Bn abc Bo abc Bp abc Bq abc Br abc Bs abc Bt abc Bu abc Bv abc Bw abc Bx abc By abc

%
%设置计数0
0
%#不要为这个“for”循环操心。它只是用于生成输入
%对于{set i 65}{$i<123}{incr i}{
如果{$count==101}中断
如果{$i>=90&&$i=90&&$j@strib:不是重复的。那边的解决方案不太理想。让我们把这个问题留待讨论。不允许替换n个实例。只有1个或
-ALL
，这就是为什么这里不能使用正则表达式。@strib:不是重复的。那边的解决方案不太理想。让我们把这个问题留待讨论。不是吗现在替换n个实例。只有1个或
-ALL
，这就是为什么这里不能使用regex。我们不能使用regsub实现吗？@Bharathi不，这是不可能的。re_语法无法基于匹配限制替换。我们不能使用regsub实现吗？@Bharathi不，这是不可能的。re_语法无法基于在比赛中。