How can I start an interactive console for Perl

Question

How can I start an interactive console for Perl  similar to the irb command for Ruby or python for Python

User · Answer

Update  I ve since created a downloadable REPL - see my other answer   With the benefit of hindsight    The third-party solutions mentioned among the existing answers are either cumbersome to install and or do not work without non-trivial  non-obvious additional steps - some solutions appear to be at least half-abandoned  A usable REPL needs the readline library for command-line-editing keyboard support and history support - ensuring this is a trouble spot for many third-party solutions  If you install CLI rlwrap  which provides readline support to any command  you can combine it with a simple Perl command to create a usable REPL  and thus make do without third-party REPL solutions    On OSX  you can install rlwrap via Homebrew with brew install rlwrap  Linux distros should offer rlwrap via their respective package managers  e g   on Ubuntu  use sudo apt-get install rlwrap  See J  n S  ren  k s answer for said combination of rlwrap and a Perl command       What you do NOT get with J  n s answer    auto-completion ability to enter multi-line statements   The only third-party solution that offers these  with non-trivial installation   additional  non-obvious steps   is psh  but    it hasn t seen activity in around 2 5 years its focus is different in that it aims to be a full-fledged shell replacement  and thus works like a traditional shell  which means that it doesn t automatically evaluate a command as a Perl statement  and requires an explicit output command such as print to print the result of an expression      J  n S  ren  k s answer can be improved in one way    By default  it prints arrays lists hashtables as scalars  i e   only prints their element count  whereas it would be handy to enumerate their elements instead    If you install the Data  Printer module with  sudo  cpan Data  Printer as a one-time operation  you can load it into the REPL for use of the p   function  to which you can pass lists arrays hashtables for enumeration   Here s an alias named iperl with readline and Data  Printer support  which can you put in your POSIX-like shell s initialization file  e g      bashrc    alias iperl  rlwrap -A -S  iperl gt    perl -MData  Printer -wnE     BEGIN   say    Use  p   lt arrayOrList gt   or  p   lt hashTable gt   to print arrays lists hashtables  e g    p  ENV      say eval            E g   you can then do the following to print all environment variables via hashtable  ENV     iperl          start the REPL iperl gt  p  ENV    print key-value pairs in hashtable  ENV   As with J  n s answer  the scalar result of an expression is automatically printed  e g    iperl gt  22   7    automatically print scalar result of expression  3 14285714285714

User · Answer

I use the command line as a console     perl -e  print  JAPH n     Then I can use my bash history to get back old commands   This does not preserve state  however   This form is most useful when you want to test  one little thing   like when answering Perl questions    Often  I find these commands get scraped verbatim into a shell script  or makefile

User · Answer

Perl doesn t have a console but the debugger can be used as one  At a command prompt  type perl -de 1   The value  1  doesn t matter  it s just a valid statement that does nothing    There are also a couple of options for a Perl shell   For more information read perlfaq3

User · Answer

You can use the perl debugger on a trivial program  like so   perl -de1   Alternatively there s Alexis Sukrieh s Perl Console application  but I haven t used it

User · Answer

You can always just drop into the built-in debugger and run commands from there      perl -d -e 1

User · Answer

If you want history  use rlwrap  This could be your   bin ips for example      bin sh echo  This is Interactive Perl shell  rlwrap -A -pgreen -S perl gt    perl -wnE say eval          And this is how it looks like     ips This is Interactive Perl shell perl gt  2  128 3 40282366920938e 38 perl gt

User · Answer

I ve created perli  a Perl REPL that runs on Linux  macOS  and Windows   Its focus is automatic result printing  convenient documentation lookups  and easy inspection of regular-expression matches  You can see screenshots here   It works stand-alone  has no dependencies other than Perl itself   but installation of rlwrap is strongly recommended so as to support command-line editing  persistent command history  and tab-completion - read more here   Installation   If you happen to have Node js installed   npm install -g perli  Otherwise    Unix-like platforms  Download this script as perli to a folder in your system s path and make it executable with chmod  x  Windows  Download the this script as perli pl  note the  pl extension  to a folder in your system s path  If you don t mind invoking Perli as perli pl  you re all set  Otherwise  create a batch file named perli cmd in the same folder with the following content     dpn pl     this enables invocation as just perli

User · Answer

Perl doesn t have a console but the debugger can be used as one  At a command prompt  type perl -de 1   The value  1  doesn t matter  it s just a valid statement that does nothing    There are also a couple of options for a Perl shell   For more information read perlfaq3

User · Answer

Update  I ve since created a downloadable REPL - see my other answer   With the benefit of hindsight    The third-party solutions mentioned among the existing answers are either cumbersome to install and or do not work without non-trivial  non-obvious additional steps - some solutions appear to be at least half-abandoned  A usable REPL needs the readline library for command-line-editing keyboard support and history support - ensuring this is a trouble spot for many third-party solutions  If you install CLI rlwrap  which provides readline support to any command  you can combine it with a simple Perl command to create a usable REPL  and thus make do without third-party REPL solutions    On OSX  you can install rlwrap via Homebrew with brew install rlwrap  Linux distros should offer rlwrap via their respective package managers  e g   on Ubuntu  use sudo apt-get install rlwrap  See J  n S  ren  k s answer for said combination of rlwrap and a Perl command       What you do NOT get with J  n s answer    auto-completion ability to enter multi-line statements   The only third-party solution that offers these  with non-trivial installation   additional  non-obvious steps   is psh  but    it hasn t seen activity in around 2 5 years its focus is different in that it aims to be a full-fledged shell replacement  and thus works like a traditional shell  which means that it doesn t automatically evaluate a command as a Perl statement  and requires an explicit output command such as print to print the result of an expression      J  n S  ren  k s answer can be improved in one way    By default  it prints arrays lists hashtables as scalars  i e   only prints their element count  whereas it would be handy to enumerate their elements instead    If you install the Data  Printer module with  sudo  cpan Data  Printer as a one-time operation  you can load it into the REPL for use of the p   function  to which you can pass lists arrays hashtables for enumeration   Here s an alias named iperl with readline and Data  Printer support  which can you put in your POSIX-like shell s initialization file  e g      bashrc    alias iperl  rlwrap -A -S  iperl gt    perl -MData  Printer -wnE     BEGIN   say    Use  p   lt arrayOrList gt   or  p   lt hashTable gt   to print arrays lists hashtables  e g    p  ENV      say eval            E g   you can then do the following to print all environment variables via hashtable  ENV     iperl          start the REPL iperl gt  p  ENV    print key-value pairs in hashtable  ENV   As with J  n s answer  the scalar result of an expression is automatically printed  e g    iperl gt  22   7    automatically print scalar result of expression  3 14285714285714

User · Answer

Not only did Matt Trout write an article about a REPL  he actually wrote one - Devel  REPL  I ve used it a bit and it works fairly well  and it s under active development   BTW  I have no idea why someone modded down the person who mentioned using  perl -e  from the console  This isn t really a REPL  true  but it s fantastically useful  and I use it all the time

User · Answer

There isn t an interactive console for Perl built in like Python does   You can however use the Perl Debugger to do debugging related things   You turn it on with the -d option  but you might want to check out  man perldebug  to learn about it     After a bit of googling  there is a separate project that implements a Perl console which you can find at http   www sukria net perlconsole html   Hope this helps

User · Answer

perl -d is your friend     perl -de 0

User · Answer

I wrote a script I call  psh        usr bin perl  while   lt  gt       chomp    my  result   eval    print        result n       Whatever you type in  it evaluates in Perl    gt  gmtime 2  30  gmtime 2  30    Sat Jan 10 13 37 04 2004   gt   x    foo   x    foo    foo   gt   x    s o a g  x    s o a g   2   gt   x  x   faa

User · Answer

You could look into psh here  http   gnp github io psh   It s a full on shell  you can use it in replacement of bash for example   but uses perl syntax   so you can create methods on the fly etc

User · Answer

Matt Trout s overview lists five choices  from perl -de 0 onwards  and he recommends Reply  if extensibility via plugins is important  or tinyrepl from Eval  WithLexicals  for a minimal  pure-perl solution that includes readline support and lexical persistence

User · Answer

I wrote a script I call  psh        usr bin perl  while   lt  gt       chomp    my  result   eval    print        result n       Whatever you type in  it evaluates in Perl    gt  gmtime 2  30  gmtime 2  30    Sat Jan 10 13 37 04 2004   gt   x    foo   x    foo    foo   gt   x    s o a g  x    s o a g   2   gt   x  x   faa

User · Answer

I use the command line as a console     perl -e  print  JAPH n     Then I can use my bash history to get back old commands   This does not preserve state  however   This form is most useful when you want to test  one little thing   like when answering Perl questions    Often  I find these commands get scraped verbatim into a shell script  or makefile

User · Answer

You could look into psh here  http   gnp github io psh   It s a full on shell  you can use it in replacement of bash for example   but uses perl syntax   so you can create methods on the fly etc

User · Answer

Read-eval-print loop     perl -e while  lt  gt   print eval   n

User · Answer

There isn t an interactive console for Perl built in like Python does   You can however use the Perl Debugger to do debugging related things   You turn it on with the -d option  but you might want to check out  man perldebug  to learn about it     After a bit of googling  there is a separate project that implements a Perl console which you can find at http   www sukria net perlconsole html   Hope this helps

User · Answer

Sepia and PDE have also own REPLs  for GNU Emacs

User · Answer

re pl from Devel  REPL

User · Answer

I always did   rlwrap perl -wlne eval print  if      With 5 10  I ve switched to   rlwrap perl -wnE say eval           rlwrap is optional

User · Answer

I think you re asking about a REPL  Read  Evaluate  Print  Loop  interface to perl  There are a few ways to do this    Matt Trout has an article that describes how to write one Adriano Ferreira has described some options and finally  you can hop on IRC at irc perl org and try out one of the eval bots in many of the popular channels  They will evaluate chunks of perl that you pass to them

User · Answer

I use the command line as a console     perl -e  print  JAPH n     Then I can use my bash history to get back old commands   This does not preserve state  however   This form is most useful when you want to test  one little thing   like when answering Perl questions    Often  I find these commands get scraped verbatim into a shell script  or makefile

User · Answer

You can use the perl debugger on a trivial program  like so   perl -de1   Alternatively there s Alexis Sukrieh s Perl Console application  but I haven t used it

User · Answer

Also look for ptkdb on CPAN  http   search cpan org search query ptkdb amp mode all

User · Answer

Matt Trout s overview lists five choices  from perl -de 0 onwards  and he recommends Reply  if extensibility via plugins is important  or tinyrepl from Eval  WithLexicals  for a minimal  pure-perl solution that includes readline support and lexical persistence

User · Answer

Not only did Matt Trout write an article about a REPL  he actually wrote one - Devel  REPL  I ve used it a bit and it works fairly well  and it s under active development   BTW  I have no idea why someone modded down the person who mentioned using  perl -e  from the console  This isn t really a REPL  true  but it s fantastically useful  and I use it all the time

User · Answer

re pl from Devel  REPL

User · Answer

Not only did Matt Trout write an article about a REPL  he actually wrote one - Devel  REPL  I ve used it a bit and it works fairly well  and it s under active development   BTW  I have no idea why someone modded down the person who mentioned using  perl -e  from the console  This isn t really a REPL  true  but it s fantastically useful  and I use it all the time

User · Answer

Sepia and PDE have also own REPLs  for GNU Emacs

User · Answer

I think you re asking about a REPL  Read  Evaluate  Print  Loop  interface to perl  There are a few ways to do this    Matt Trout has an article that describes how to write one Adriano Ferreira has described some options and finally  you can hop on IRC at irc perl org and try out one of the eval bots in many of the popular channels  They will evaluate chunks of perl that you pass to them

User · Answer

You can always just drop into the built-in debugger and run commands from there      perl -d -e 1

User · Answer

You can use the perl debugger on a trivial program  like so   perl -de1   Alternatively there s Alexis Sukrieh s Perl Console application  but I haven t used it

User · Answer

I wrote a script I call  psh        usr bin perl  while   lt  gt       chomp    my  result   eval    print        result n       Whatever you type in  it evaluates in Perl    gt  gmtime 2  30  gmtime 2  30    Sat Jan 10 13 37 04 2004   gt   x    foo   x    foo    foo   gt   x    s o a g  x    s o a g   2   gt   x  x   faa

User · Answer

There are two popular Perl REPLs    Devel  REPL is great  But IMO Reply is better

User · Answer

re pl from Devel  REPL

User · Answer

Also look for ptkdb on CPAN  http   search cpan org search query ptkdb amp mode all

User · Answer

Perl doesn t have a console but the debugger can be used as one  At a command prompt  type perl -de 1   The value  1  doesn t matter  it s just a valid statement that does nothing    There are also a couple of options for a Perl shell   For more information read perlfaq3

User · Answer

Not only did Matt Trout write an article about a REPL  he actually wrote one - Devel  REPL  I ve used it a bit and it works fairly well  and it s under active development   BTW  I have no idea why someone modded down the person who mentioned using  perl -e  from the console  This isn t really a REPL  true  but it s fantastically useful  and I use it all the time

User · Answer

I always did   rlwrap perl -wlne eval print  if      With 5 10  I ve switched to   rlwrap perl -wnE say eval           rlwrap is optional

User · Answer

I always did   rlwrap perl -wlne eval print  if      With 5 10  I ve switched to   rlwrap perl -wnE say eval           rlwrap is optional

User · Answer

You can do it online  like many things in life  here   https   www tutorialspoint com execute perl online php

User · Answer

Under Debian Ubuntu     sudo apt-get install libdevel-repl-perl   re pl    sudo apt-get install libapp-repl-perl   iperl

User · Answer

See also Stylish REPL  for GNU Emacs  http   blog jrock us articles Stylish 20REPL pod

User · Answer

I use the command line as a console     perl -e  print  JAPH n     Then I can use my bash history to get back old commands   This does not preserve state  however   This form is most useful when you want to test  one little thing   like when answering Perl questions    Often  I find these commands get scraped verbatim into a shell script  or makefile

User · Answer

I always did   rlwrap perl -wlne eval print  if      With 5 10  I ve switched to   rlwrap perl -wnE say eval           rlwrap is optional

User · Answer

See also Stylish REPL  for GNU Emacs  http   blog jrock us articles Stylish 20REPL pod

User · Answer

You could look into psh here  http   gnp github io psh   It s a full on shell  you can use it in replacement of bash for example   but uses perl syntax   so you can create methods on the fly etc

User · Answer

Also look for ptkdb on CPAN  http   search cpan org search query ptkdb amp mode all

User · Answer

I think you re asking about a REPL  Read  Evaluate  Print  Loop  interface to perl  There are a few ways to do this    Matt Trout has an article that describes how to write one Adriano Ferreira has described some options and finally  you can hop on IRC at irc perl org and try out one of the eval bots in many of the popular channels  They will evaluate chunks of perl that you pass to them

User · Answer

You can use the perl debugger on a trivial program  like so   perl -de1   Alternatively there s Alexis Sukrieh s Perl Console application  but I haven t used it

User · Answer

I think you re asking about a REPL  Read  Evaluate  Print  Loop  interface to perl  There are a few ways to do this    Matt Trout has an article that describes how to write one Adriano Ferreira has described some options and finally  you can hop on IRC at irc perl org and try out one of the eval bots in many of the popular channels  They will evaluate chunks of perl that you pass to them

User · Answer

Also look for ptkdb on CPAN  http   search cpan org search query ptkdb amp mode all

User · Answer

You can always just drop into the built-in debugger and run commands from there      perl -d -e 1

User · Answer

Perl doesn t have a console but the debugger can be used as one  At a command prompt  type perl -de 1   The value  1  doesn t matter  it s just a valid statement that does nothing    There are also a couple of options for a Perl shell   For more information read perlfaq3

User · Answer

Read-eval-print loop     perl -e while  lt  gt   print eval   n

User · Answer

You can always just drop into the built-in debugger and run commands from there      perl -d -e 1

User · Answer

If you want history  use rlwrap  This could be your   bin ips for example      bin sh echo  This is Interactive Perl shell  rlwrap -A -pgreen -S perl gt    perl -wnE say eval          And this is how it looks like     ips This is Interactive Perl shell perl gt  2  128 3 40282366920938e 38 perl gt

User · Answer

You can do it online  like many things in life  here   https   www tutorialspoint com execute perl online php

User · Answer

perl -d is your friend     perl -de 0

User · Answer

See also Stylish REPL  for GNU Emacs  http   blog jrock us articles Stylish 20REPL pod

User · Answer

re pl from Devel  REPL

User · Answer

You could look into psh here  http   gnp github io psh   It s a full on shell  you can use it in replacement of bash for example   but uses perl syntax   so you can create methods on the fly etc

User · Answer

There isn t an interactive console for Perl built in like Python does   You can however use the Perl Debugger to do debugging related things   You turn it on with the -d option  but you might want to check out  man perldebug  to learn about it     After a bit of googling  there is a separate project that implements a Perl console which you can find at http   www sukria net perlconsole html   Hope this helps

User · Answer

perl -d is your friend     perl -de 0

User · Answer

I wrote a script I call  psh        usr bin perl  while   lt  gt       chomp    my  result   eval    print        result n       Whatever you type in  it evaluates in Perl    gt  gmtime 2  30  gmtime 2  30    Sat Jan 10 13 37 04 2004   gt   x    foo   x    foo    foo   gt   x    s o a g  x    s o a g   2   gt   x  x   faa

User · Answer

There are two popular Perl REPLs    Devel  REPL is great  But IMO Reply is better

User · Answer

See also Stylish REPL  for GNU Emacs  http   blog jrock us articles Stylish 20REPL pod

User · Answer

There isn t an interactive console for Perl built in like Python does   You can however use the Perl Debugger to do debugging related things   You turn it on with the -d option  but you might want to check out  man perldebug  to learn about it     After a bit of googling  there is a separate project that implements a Perl console which you can find at http   www sukria net perlconsole html   Hope this helps

User · Answer

Sepia and PDE have also own REPLs  for GNU Emacs

User · Answer

Under Debian Ubuntu     sudo apt-get install libdevel-repl-perl   re pl    sudo apt-get install libapp-repl-perl   iperl

User · Answer

Sepia and PDE have also own REPLs  for GNU Emacs

User · Answer

perl -d is your friend     perl -de 0

User · Answer

I ve created perli  a Perl REPL that runs on Linux  macOS  and Windows   Its focus is automatic result printing  convenient documentation lookups  and easy inspection of regular-expression matches  You can see screenshots here   It works stand-alone  has no dependencies other than Perl itself   but installation of rlwrap is strongly recommended so as to support command-line editing  persistent command history  and tab-completion - read more here   Installation   If you happen to have Node js installed   npm install -g perli  Otherwise    Unix-like platforms  Download this script as perli to a folder in your system s path and make it executable with chmod  x  Windows  Download the this script as perli pl  note the  pl extension  to a folder in your system s path  If you don t mind invoking Perli as perli pl  you re all set  Otherwise  create a batch file named perli cmd in the same folder with the following content     dpn pl     this enables invocation as just perli

[perl] How can I start an interactive console for Perl?

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