Addons/api/jc

+overview
J bindings for C library routines and stdin/stdout tasks
J uses C name except that fopen is sopen etc.

+stream
  s=. sopen_jc_  'foo.txt';'w'
  s=. sdopen_jc_ fd;'w'
      sclose_jc_ s
      swrite_jc_ s;'data'
  d=. sread_jc_  s,n or _1 for all
  b=. stell_jc_  s
      sseek_jc_  s,n   

+fd (file descriptors)
  f=. open_jc_  'foo.txt';'rdwr creat nonblock'
      close_jc_ f
      write_jc_ f;'data'
  d=. read_jc_  r,n or _1 for all
  b=. tell_jc_  f
      seek_jc_  f,n
      
+file names
      unlink_jc_ 'foo.txt'

+system
  stdin/stdout/stderr redirection supported
      system_jc_  'ls -l >foo.txt'
      system_jc_  'sleep 5'
      system_jc_  'sleep 20 &'
      systemr_jc_ 'ls -l'     NB. return stdout

      system_jc_  'dir'
      systemr_jc_ 'dir'

+run task (stdin/stdout) and return stdout
  J=: '/jconsole',~jpath'~bin'
      J run_jc_ 'i.2 3 4',LF,'BINPATH',LF
      J run_jc_ 'i.23';'|.BINPATH'
      J run_jc_ fread'...'
        
      'bash'run_jc_'cd gitdev';'ls'

+run task interactively
  not in windows because no tail to feed new lines to stdin
  b=: 'bash'conew'jc'
      do__b'ps -a'
      gt__b 0 NB. wait 0 seconds for output
      destroy__b
        
  j=: ('/jconsole',~jpath'~bin')conew'jc'
      do__j'|.BINPATH'
      do__j'i.3 4'
      gt__j 0 NB. note 3 blank prompt in front of 0
      do__j'i.23[6!:3[5' NB. no output for 5 secs
      gt__j 0 NB. no output
      gt__j 8 NB. poll for 8 secs until there is output
      fread pout__j NB. read output file
      
+clean stdout
  start of output for an input is not marked
  stdout has prompts that can mess up display
  display can be improved by replacing prompts with LFs
      '   ' clean_jc_ fread stdout_file NB. replace '   ' prompt with LFs
      
+windows
  UTF-8 not supported
   requires conversion to wchar and use of wchar routines
   
  system adds 'cmd /s /c ' to arg as this helps with quotes

  system & (background) not supported in windows

  run task interactively - not supported in windows
   unix facility uses tail to pipe new lines to command

  fd open/close leaves file such that ferase/unlink fail
   restart does not clear the problem!
   windows explorer delete works!
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