Shell Programming and Scripting

sed -ne 's/[^-<>]*\([-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*\).*\([-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*\).*/\1\2/p'

->stockholm->paris<-stockholmpi<-tokyo->paris<-stockholmpi
->stockholm<-stockholm->tokyo<-tokyo<-paris->stockholmtao
->paris<-stockholm<-tokyo<-paris<-tokyo->stockholm
<-tokyo<-stockholm->tokyo<-tokyo->stockholm->paris

Wed3.14153<-paris<-stockholm->tokyo'->paris<-stockholm->parisphi$$
fubartao<-tokyo<-stockholm<-tokyoJul->paris->tokyo<-parisRed3.14153
$chi<-tokyo<-paris<-stockholmMar->tokyo<-stockholm->tokyoGreen 
Feb3.14153<-tokyo->tokyo<-parisBLACK<-paris<-tokyo->tokyoMar 
1011102.8<-stockholm<-tokyo<-tokyoblah<-stockholm<-stockholm<-tokyo3.14153001111
taoBLACK<-tokyo->paris->paris ->stockholm<-paris->stockholmThu3.14153
MayJun<-paris->paris<-stockholmSun->stockholm->tokyo->stockholm011011Green
NILLNULL->tokyo<-paris<-parisSep->stockholm->tokyo<-parisJunFri
AugFeb->stockholm<-stockholm->parisBLACK<-tokyo<-paris<-tokyoVOIDpi
 <-paris->paris->parisfoo->stockholm->paris->stockholm$NULL
chi3.14153<-paris<-paris<-tokyofoo<-stockholm<-paris->stockholm`100110
foo$$<-tokyo<-stockholm<-stockholm101101<-paris<-tokyo<-tokyo"Purple
fubarPurple->tokyo<-paris->paris ->tokyo<-paris<-tokyo`3.14
BlueMay->paris->stockholm<-stockholmVOID->stockholm->paris<-tokyoYellowphi
0101002.8<-tokyo->paris<-tokyotao<-tokyo<-tokyo->stockholmfooNULL
RedWed->paris->paris<-stockholmNILL<-tokyo<-paris->tokyoPurple 
100100$$$->paris->paris<-tokyo001011<-paris->paris->tokyoMonSep
Jan010001->paris->paris<-stockholmAug->tokyo<-paris->stockholmPurpleSep
->paris->paris<-tokyoblah<-stockholm<-stockholm<-paris010001tao
Purplefubar->stockholm<-paris->tokyoDec->paris->stockholm->tokyo$3.1415
010001->paris<-stockholm->tokyoVOID->tokyo<-stockholm<-tokyoMarFeb
SunFri->tokyo->paris<-tokyoJan->paris<-stockholm->tokyoWHITEMon

 ->stockholm->paris<-stockholmpi<-tokyo->paris<-stockholmpi

[stockholm,paris,tokyo]*

sed -ne 's/[^-<>]*\([-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*\).*\([-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}[stockholm,paris,tokyo]*[-><]\{2\}
\(stockholm\|paris\|tokyo\)\{1\}\).*/{Phil}2053,\1{5872Phil}\2[->->]/p' datasets/q14target.txt

awk '
BEGIN   {for (n=split("stockholm paris tokyo", T); n>0; n--) C[T[n]] = n
        }
        {for (i=1; i<=NF; i++)  {V = ""
                                 for (c in C) if ($i ~ c) V = c
                                 sub (/[^<>]+/, V, $i)
                                 printf "%s%s", $i, (i<NF)?FS:""
                                }
         printf "\n"
        }
' FS="-" file
<-paris<-stockholm->tokyo->paris<-stockholm->paris
<-tokyo<-stockholm<-tokyo->paris->tokyo<-paris
<-tokyo<-paris<-stockholm->tokyo<-stockholm->tokyo
<-tokyo->tokyo<-paris<-paris<-tokyo->tokyo
<-stockholm<-tokyo<-tokyo<-stockholm<-stockholm<-tokyo
<-tokyo->paris->paris->stockholm<-paris->stockholm
.
.
.

awk '
BEGIN   {for (n=split("stockholm paris tokyo", T); n>0; n--) C[T[n]] = n
        }
        {for (i=1; i<=NF; i++)  {V = ""
                                 for (c in C) if ($i ~ c) V = c
                                 sub (/[^<>]+/, V, $i)
                                }
        }
1
' FS="-" OFS="-" file