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utils-extra

Collection of extra tools for Unixes

lolcat.c (1879B)

    

  1. // utils-extra: Collection of extra tools for Unixes
  2. // SPDX-FileCopyrightText: 2017-2022 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: MPL-2.0
  5. #define _POSIX_C_SOURCE 200809L
  6. #include <errno.h>  /* errno */
  7. #include <math.h>   /* sin() */
  8. #include <stdio.h>  /* fgetc(), fputc(), printf(), fopen(), fclose() */
  9. #include <string.h> /* strerror() */
  11. void
  12. rainbow(double freq, int i)
  13. {
  14. 	double red, green, blue;
  15. 	double pi = 3.14159;
  17. 	red   = sin(freq * i + 0) * 127 + 128;
  18. 	green = sin(freq * i + 2 * pi / 3) * 127 + 128;
  19. 	blue  = sin(freq * i + 4 * pi / 3) * 127 + 128;
  21. 	printf("[38;2;%02d;%02d;%02dm", (int)red, (int)green, (int)blue);
  22. }
  24. int
  25. concat(FILE *stream)
  26. {
  27. 	double freq = 0.1;
  28. 	int i       = 0;
  30. 	int c;
  31. 	errno = 0;
  32. 	while((c = fgetc(stream)) != EOF)
  33. 	{
  34. 		rainbow(freq, i);
  35. 		i++;
  36. 		if(c == '')
  37. 		{
  38. 			printf("^[");
  39. 			continue;
  40. 		}
  42. 		if(fputc(c, stdout) == EOF)
  43. 		{
  44. 			fprintf(stderr, "\nlolcat: Write error: %s\n", strerror(errno));
  45. 			return 1;
  46. 		}
  47. 	}
  49. 	if(c == EOF && errno != 0)
  50. 	{
  51. 		fprintf(stderr, "\nlolcat: Read error: %s\n", strerror(errno));
  52. 		return 1;
  53. 	}
  55. 	return 0;
  56. }
  58. int
  59. main(int argc, char *argv[])
  60. {
  61. 	int ret = 0;
  63. 	if(argc <= 1)
  64. 	{
  65. 		ret = concat(stdin);
  66. 		goto end;
  67. 	}
  69. 	for(int argi = 1; argi < argc; argi++)
  70. 	{
  71. 		if(strncmp(argv[argi], "-", 2) == 0)
  72. 		{
  73. 			ret = concat(stdin);
  74. 			if(ret != 0)
  75. 			{
  76. 				goto end;
  77. 			}
  78. 		}
  79. 		else if(strncmp(argv[argi], "--", 3) == 0)
  80. 		{
  81. 			continue;
  82. 		}
  83. 		else
  84. 		{
  85. 			FILE *file = fopen(argv[argi], "r");
  87. 			if(!file)
  88. 			{
  89. 				fprintf(stderr, "\nlolcat: Error opening ‘%s’: %s\n", argv[argi], strerror(errno));
  90. 				ret = 1;
  91. 				goto end;
  92. 			}
  93. 			else
  94. 			{
  95. 				ret = concat(file);
  96. 				if(ret != 0)
  97. 				{
  98. 					goto end;
  99. 				}
  101. 				ret = fclose(file);
  102. 				if(ret != 0)
  103. 				{
  104. 					goto end;
  105. 				}
  106. 			}
  107. 		}
  108. 	}
  110. end:
  111. 	printf("");
  112. 	return ret;
  113. }