How to output to a log a multi-level array in a format that is human-readable

Question

I m working on a drupal site and when debugging  I am always having to read through long  nested arrays  As a result  a large portion of my life is spent using the arrow  return  and tab keys  to split up 1000  character strings into a nested  readable format   For drupal devs  I can t use devel s dsm    as I m working with multi-step  ahah  ajax forms  and I can only output the arrays to the error log  not to the screen   Visual example   Evil   array    form wrapper     array     tree     true    type      fieldset     prefix           suffix           value          name     array     type      textfield     title     NULL    size     60    maxlength     60    required     false    description     NULL    attributes     array    placeholder      Email        post     array    form wrapper     array    name          pass                 Good   array     form wrapper    gt  array          tree    gt  true         type    gt   fieldset          prefix    gt    lt div gt           suffix    gt    lt  div gt           value    gt            name    gt  array              type    gt   textfield              title    gt  NULL             size    gt  60             maxlength    gt  60             required    gt  false             description    gt  NULL             attributes    gt  array                 placeholder    gt   Email                  Edit  Sorry  by  not output to screen   I meant via drupal s system messages where it s possible to output arrays in a clickable  nested format  using devel module

User · Answer

Syntax print r variable  return    variable    Required  Specifies the variable to return information about return      Optional  When set to true  this function will return the information  not print it   Default is false Example error log  print r  lt array Variable gt   TRUE

User · Answer

Simple stuff   Using print r  var dump or var export should do it pretty nicely if you look at the result in view-source mode not in HTML mode or as  Joel Larson said if you wrap everything in a  lt pre gt  tag   print r is best for readability but it doesn t print null false values   var dump is best for checking types of values and lengths and null false values   var export is simmilar to var dump but it can be used to get the dumped string   The format returned by any of these is indented correctly in the source code and var export can be used for logging since it can be used to return the dumped string   Advanced stuff   Use the xdebug plug-in for PHP this prints var dumps as HTML formatted strings not as raw dump format and also allows you to supply a custom function you want to use for formatting

User · Answer

This will help you  echo   lt pre gt      output   print r  array 1     echo   lt  pre gt     EDIT  using echo   lt pre gt    is useless  but var export  var   will do the thing which you are expecting

User · Answer

http   php net manual en function print-r php  This function can be used to format output     output   print r  array 1      output is a string variable  it can be logged like every other string  In pure php you can use trigger error  Ex  trigger error  output    http   php net manual en function trigger-error php  if you need to format it also in html  you can use  lt pre gt  tag

User · Answer

I just wonder why nobody uses or recommends the way I prefer to debug an array  error log json encode  array     Next to my browser I tail my server log in the console eg  tail -f  var log apache2 error log

User · Answer

If you need to log an error to Apache error log you can try this   error log  print r  multidimensionalarray  TRUE

User · Answer

You should be able to use a var dump   within a pre tag  Otherwise you could look into using  a library like dump r php  https   github com leeoniya dump r php  My solution is incorrect  OP was looking for a solution formatted with spaces to store in a log file   A solution might be to use output buffering with var dump  then str replace   all the tabs with spaces to format it in the log file

User · Answer

Drupal s Devel module has other useful functions including ones that can print formatted arrays and objects to log files  See the guide at http   ratatosk net drupal tutorials debugging-drupal html     dd        Logs any variable to a file named    drupal debug txt    in the   site   s temp directory  All output from this function is appended to   the log file  making it easy to see how the contents of a variable   change as you modify your code       If you   re using Mac OS X you can use the Logging Console to monitor   the contents of the log file       If you   re using a flavor of Linux you can use the command    tail -f   drupal debug txt    to watch the data being logged to the file

[php] How to output (to a log) a multi-level array in a format that is human-readable?

Examples related to php

Examples related to drupal