{"id":35,"date":"2004-05-01T00:18:57","date_gmt":"2004-04-30T22:18:57","guid":{"rendered":"http:\/\/frenchfragfactory.net\/ozh\/archives\/2004\/05\/01\/perl-one-liners\/"},"modified":"2007-05-09T23:33:48","modified_gmt":"2007-05-09T21:33:48","slug":"perl-one-liners","status":"publish","type":"post","link":"https:\/\/planetozh.com\/blog\/2004\/05\/perl-one-liners\/","title":{"rendered":"Perl one-liners"},"content":{"rendered":"

Collection of Perl one liners. The Camel ownz j00 all :)
\n<\/p>\n

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\n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
perl<\/div>\n\n\t\t\n\t\t
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  1. # run contents of "my_file" as a program<\/span><\/div><\/li>\n
  2. $ perl my_file<\/div><\/li>\n
  3.  <\/div><\/li>\n
  4. # run debugger "stand-alone"<\/span><\/div><\/li>\n
  5. $ perl -<\/span>d -<\/span>e 42<\/span><\/div><\/li>\n
  6.  <\/div><\/li>\n
  7. # run program, but with warnings<\/span><\/div><\/li>\n
  8. $ perl -<\/span>w my_file<\/div><\/li>\n
  9.  <\/div><\/li>\n
  10. # run program under debugger<\/span><\/div><\/li>\n
  11. $ perl -<\/span>d my_file<\/div><\/li>\n
  12.  <\/div><\/li>\n
  13. # just check syntax, with warnings<\/span><\/div><\/li>\n
  14. $ perl -<\/span>wc my_file<\/div><\/li>\n
  15.  <\/div><\/li>\n
  16. # useful at end of "find foo -print"<\/span><\/div><\/li>\n
  17. $ perl -<\/span>nle unlink<\/span><\/div><\/li>\n
  18.  <\/div><\/li>\n
  19. # simplest one-liner program<\/span><\/div><\/li>\n
  20. $ perl -<\/span>e 'print "hello world! "'<\/span><\/div><\/li>\n
  21.  <\/div><\/li>\n
  22. # add first and penultimate columns<\/span><\/div><\/li>\n
  23. $ perl -<\/span>lane 'print $F[0] + $F[-2]'<\/span><\/div><\/li>\n
  24.  <\/div><\/li>\n
  25. # just lines 15 to 17<\/span><\/div><\/li>\n
  26. $ perl -<\/span>ne<\/span> 'print if 15 .. 17'<\/span> *.<\/span>pod<\/div><\/li>\n
  27.  <\/div><\/li>\n
  28. # in-place edit of *.c files changing all foo to bar<\/span><\/div><\/li>\n
  29. $ perl -<\/span>p -<\/span>i.<\/span>bak -<\/span>e 's\/\\bfoo&\\b\/bar\/g'<\/span> *.<\/span>c<\/div><\/li>\n
  30.  <\/div><\/li>\n
  31. # command-line that prints the first 50 lines (cheaply)<\/span><\/div><\/li>\n
  32. $ perl -<\/span>pe 'exit if $. > 50'<\/span> f1 f2 f3 ...<\/span><\/div><\/li>\n
  33.  <\/div><\/li>\n
  34. # delete first 10 lines<\/span><\/div><\/li>\n
  35. $ perl -<\/span>i.<\/span>old -<\/span>ne<\/span> 'print unless 1 .. 10'<\/span> foo.<\/span>txt<\/div><\/li>\n
  36.  <\/div><\/li>\n
  37. # change all the isolated oldvar occurrences to newvar<\/span><\/div><\/li>\n
  38. $ perl -<\/span>i.<\/span>old -<\/span>pe 's{\\boldvar\\b}{newvar}g'<\/span> *.<\/span>[<\/span>chy]<\/span><\/div><\/li>\n
  39.  <\/div><\/li>\n
  40. # command-line that reverses the whole file by lines<\/span><\/div><\/li>\n
  41. $ perl -<\/span>e 'print reverse <>'<\/span> file1 file2 file3 ....<\/span><\/div><\/li>\n
  42.  <\/div><\/li>\n
  43. # find palindromes<\/span><\/div><\/li>\n
  44. $ perl -<\/span>lne 'print if $_ eq reverse'<\/span> \/<\/span>usr\/<\/span>dict\/<\/span>words<\/div><\/li>\n
  45.  <\/div><\/li>\n
  46. # command-line that reverse all the bytes in a file<\/span><\/div><\/li>\n
  47. $ perl -<\/span>0777e 'print scalar reverse <>'<\/span> f1 f2 f3 ...<\/span><\/div><\/li>\n
  48.  <\/div><\/li>\n
  49. # command-line that reverses the whole file by paragraphs<\/span><\/div><\/li>\n
  50. $ perl -<\/span>00 -<\/span>e 'print reverse <>'<\/span> file1 file2 file3 ....<\/span><\/div><\/li>\n
  51.  <\/div><\/li>\n
  52. # increment all numbers found in these files<\/span><\/div><\/li>\n
  53. $ perl i.<\/span>tiny -<\/span>pe 's\/(d+)\/ 1 + $1 \/ge'<\/span> file1 file2 ....<\/span><\/div><\/li>\n
  54.  <\/div><\/li>\n
  55. # command-line that shows each line with its characters backwards<\/span><\/div><\/li>\n
  56. $ perl -<\/span>nle 'print scalar reverse $_'<\/span> file1 file2 file3 ....<\/span><\/div><\/li>\n
  57.  <\/div><\/li>\n
  58. # delete all but lines beween START and END<\/span><\/div><\/li>\n
  59. $ perl -<\/span>i.<\/span>old -<\/span>ne<\/span> 'print unless \/^START$\/ .. \/^END$\/'<\/span> foo.<\/span>txt<\/div><\/li>\n
  60.  <\/div><\/li>\n
  61. # binary edit (careful!)<\/span><\/div><\/li>\n
  62. $ perl -<\/span>i.<\/span>bak -<\/span>pe 's\/Mozilla\/Slopoke\/g'<\/span> \/<\/span>usr\/<\/span>local<\/span>\/<\/span>bin\/<\/span>netscape<\/div><\/li>\n
  63.  <\/div><\/li>\n
  64. # look for dup words<\/span><\/div><\/li>\n
  65. $ perl -<\/span>0777 -<\/span>ne<\/span> 'print "$.: doubled $_&\\n" while \/\\b(&\\w+)\\b\\s+\\b\\1\\b\/gi'<\/span> <\/div><\/li>\n
  66.  <\/div><\/li>\n
  67. # command-line that prints the last 50 lines (expensively)<\/span><\/div><\/li>\n
  68. $ perl -<\/span>e 'lines = <>; print @@lines[ $#lines .. $#lines-50'<\/span> f1 f2 f3 ...<\/span><\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"

    Collection of Perl one liners<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[2,3,9],"class_list":["post-35","post","type-post","status-publish","format-standard","hentry","tag-code","tag-linux","tag-perl"],"_links":{"self":[{"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/posts\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":0,"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/posts\/35\/revisions"}],"wp:attachment":[{"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/media?parent=35"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/categories?post=35"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/planetozh.com\/blog\/wp-json\/wp\/v2\/tags?post=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}