Remove a fixed prefix suffix from a string in Bash

Question

In my bash script I have a string and its prefix suffix  I need to remove the prefix suffix from the original string   For example  let s say I have the following values   string  hello-world  prefix  hell  suffix  ld    How do I get to the following result   result  o-wor

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I use grep for removing prefixes from paths  which aren t handled well by sed    echo   input    grep -oP    prefix K       K removes from the match all the characters before it

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Small and universal solution   expr   string      prefix       suffix

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foo   string  quot  prefix quot     foo   foo  quot  suffix quot     echo  quot   foo  quot  o-wor  This is documented in the Shell Parameter Expansion section of the manual     parameter word    parameter  word  The word is expanded to produce a pattern and matched according to the rules described below  see Pattern Matching   If the pattern matches the beginning of the expanded value of parameter  then the result of the expansion is the expanded value of parameter with the shortest matching pattern  the   case  or the longest matching pattern  the    case  deleted          parameter word    parameter  word  The word is expanded to produce a pattern and matched according to the rules described below  see Pattern Matching   If the pattern matches a trailing portion of the expanded value of parameter  then the result of the expansion is the value of parameter with the shortest matching pattern  the   case  or the longest matching pattern  the    case  deleted

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string  hello-world    prefix  hell    suffix  ld      remove  hell  from  hello-world  if  hell  is found at the beginning    prefix removed string   string   prefix      remove  ld  from  o-world  if  ld  is found at the end    suffix removed String   prefix removed string   suffix    echo  suffix removed String o-wor   Notes     prefix   adding   makes sure that substring  hell  is removed only if it is found in beginning    suffix   adding   makes sure that substring  ld  is removed only if it is found in end   Without these  the substrings  hell  and  ld  will get removed everywhere  even it is found in the middle

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Using sed     echo   string    sed -e  s   prefix    -e  s  suffix     o-wor   Within the sed command  the   character matches text beginning with  prefix  and the trailing   matches text ending with  suffix   Adrian Fr  hwirth makes some good points in the comments below  but sed for this purpose can be very useful  The fact that the contents of  prefix and  suffix are interpreted by sed can be either good OR bad- as long as you pay attention  you should be fine  The beauty is  you can do something like this     prefix     ll    suffix  ld     echo   string    sed -e  s   prefix    -e  s  suffix     o-wor   which may be what you want  and is both fancier and more powerful than bash variable substitution  If you remember that with great power comes great responsibility  as Spiderman says   you should be fine   A quick introduction to sed can be found at http   evc-cit info cit052 sed tutorial html  A note regarding the shell and its use of strings   For the particular example given  the following would work as well     echo  string   sed -e s   prefix   -e s  suffix         but only because    echo doesn t care how many strings are in its argument list  and There are no spaces in  prefix and  suffix   It s generally good practice to quote a string on the command line because even if it contains spaces it will be presented to the command as a single argument  We quote  prefix and  suffix for the same reason  each edit command to sed will be passed as one string  We use double quotes because they allow for variable interpolation  had we used single quotes the sed command would have gotten a literal  prefix and  suffix which is certainly not what we wanted   Notice  too  my use of single quotes when setting the variables prefix and suffix  We certainly don t want anything in the strings to be interpreted  so we single quote them so no interpolation takes place  Again  it may not be necessary in this example but it s a very good habit to get into

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Using  Adrian Fr  hwirth answer   function strip       local STRING   1    2       echo   STRING    2       use it like this  HELLO   hello   HELLO   strip   HELLO       echo  HELLO   hello

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Do you know the length of your prefix and suffix  In your case   result   echo  string   cut -c5-   rev   cut -c3-   rev    Or more general   result   echo  string   cut -c      prefix  1  -   rev   cut -c      suffix  1  -   rev    But the solution from Adrian Fr  hwirth is way cool  I didn t know about that

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I would make use of capture groups in regex     string  hello-world    prefix  hell    suffix  ld    set  H   Disables history substitution  can be omitted in scripts    perl -pe  s   prefix           suffix         suffix   1    lt  lt  lt   string o-wor   string1  string string   perl -pe  s   prefix           suffix         suffix   1 g   lt  lt  lt   string1 o-woro-wor             suffix        makes sure that the content of   suffix  will be excluded from the capture group  In terms of example  it s the string equivalent to   A-Z    Otherwise you will get     perl -pe  s   prefix       suffix   1 g   lt  lt  lt   string1 o-worldhello-wor

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Using the    operator     string  hello-world    prefix  hell    suffix  ld         string       prefix     suffix      amp  amp  echo    BASH REMATCH 1    o-wor

[bash] Remove a fixed prefix/suffix from a string in Bash

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