Shell / sed Program To Remove All C and C++ Comments From

Write the shell / sed program which remove all the comments from a simple C program stored in your current directory. You can assume that the c source code contains only syntactically correct comments:

+start with // and end with a newline

+starting with / and ending / (can be multiline)

+ nesting of comments is not allowed

Make sure that C source is not changed at all.

How do I use this sed script?

$ ./script.sed < input.c<br style="padding: 0; margin: 0"></br>$ ./script.sed < input.c > output.c<br style="padding: 0; margin: 0"></br>$ for c in *.c; do script.sed < $c > /tmp/zyzcc.c; /bin/cp -f /tmp/zyzcc.c $c; done

Sample sed code to remove all comments from sed

1. #! /bin/sed-nf
3. # Remove C and C++ comments, by Brian Hiles(brian_hiles@rocketmail.com)
5. # Sped up(and bugfixed to some extent)by Paolo Bonzini(bonzini@gnu.org)
6. # Works its way through the line, copying to hold space the text up to the
7. # first special character(/,", '). The original version went exactly a
8. # character at a time, hence the greater speed of this one. But the concept
9. # and especially the trick of building the line in hold space are entirely
10. # merit of Brian.
12. :loop
14. # This line is sufficient to remove C++ comments!
15. /^/// s,.*,,
17. /^$/{
18. x
19. p
20. n
21. b loop
22. }
23. /^"/{
24. :double
25. /^$/{
26. x
27. p
28. n
29. /^"/b break
30. b double
31. }
33. H
34. x
35. s,n(.[^"]).,1,
36. x
37. s,.[^"]*,,
39. /^"/bbreak
40. /^/{
41. H
42. x
43. s,n(.).*,1,
44. x
45. s/.//
46. }
47. b double
48. }
50. /^'/{
51. :single
52. /^$/{
53. x
54. p
55. n
56. /^'/bbreak
57. b single
58. }
59. H
60. x
61. s,n(.[^']).,1,
62. x
63. s,.[^']*,,
65. /^'/bbreak
66. /^/{
67. H
68. x
69. s,n(.).*,1,
70. x
71. s/.//
72. }
73. b single
74. }
76. /^/*/{
77. s/.//
78. :ccom
79. s,^.[^],,
80. /^$/ n
81. /^*//{
82. s/..//
83. b loop
84. }
85. b ccom
86. }
88. :break
89. H
90. x
91. s,n(.[^"'/]).,1,
92. x
93. s/.[^"'/]*//
94. b loop

原文链接: https://www.cnblogs.com/MagicLetters/archive/2013/04/14/3444258.html

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