usershell.c 3.7 KB

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  1. /*
  2. * Copyright (c) 1985, 1993
  3. * The Regents of the University of California. All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions and the following disclaimer.
  10. * 2. Redistributions in binary form must reproduce the above copyright
  11. * notice, this list of conditions and the following disclaimer in the
  12. * documentation and/or other materials provided with the distribution.
  13. * 4. Neither the name of the University nor the names of its contributors
  14. * may be used to endorse or promote products derived from this software
  15. * without specific prior written permission.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27. * SUCH DAMAGE.
  28. *
  29. * This version has been hevily modified for use with uClibc
  30. * November 2002, Erik Andersen <andersen@codepoet.org>
  31. */
  32. #include <sys/param.h>
  33. #include <sys/file.h>
  34. #include <sys/stat.h>
  35. #include <stdio.h>
  36. #include <stdio_ext.h>
  37. #include <ctype.h>
  38. #include <stdlib.h>
  39. #include <unistd.h>
  40. #include <paths.h>
  41. /*
  42. * Local shells should NOT be added here. They should be added in
  43. * /etc/shells.
  44. */
  45. static const char * const validsh[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
  46. static char **curshell, **shells, *strings;
  47. static char **initshells __P((void));
  48. /*
  49. * Get a list of shells from _PATH_SHELLS, if it exists.
  50. */
  51. char * getusershell(void)
  52. {
  53. char *ret;
  54. if (curshell == NULL)
  55. curshell = initshells();
  56. ret = *curshell;
  57. if (ret != NULL)
  58. curshell++;
  59. return (ret);
  60. }
  61. static void __free_initshell_memory(void)
  62. {
  63. if (shells != NULL) {
  64. free(shells);
  65. }
  66. shells = NULL;
  67. if (strings != NULL) {
  68. free(strings);
  69. }
  70. strings = NULL;
  71. }
  72. void endusershell(void)
  73. {
  74. __free_initshell_memory();
  75. curshell = NULL;
  76. }
  77. void setusershell(void)
  78. {
  79. curshell = initshells();
  80. }
  81. static char ** initshells(void)
  82. {
  83. register char **sp, *cp;
  84. register FILE *fp;
  85. struct stat statb;
  86. int flen;
  87. __free_initshell_memory();
  88. if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
  89. return (char **) validsh;
  90. if (fstat(fileno(fp), &statb) == -1) {
  91. goto cleanup;
  92. }
  93. if ((strings = malloc((unsigned)statb.st_size + 1)) == NULL) {
  94. goto cleanup;
  95. }
  96. if ((shells = calloc((unsigned)statb.st_size / 3, sizeof (char *))) == NULL) {
  97. goto cleanup;
  98. }
  99. /* No threads using this stream. */
  100. __fsetlocking (fp, FSETLOCKING_BYCALLER);
  101. sp = shells;
  102. cp = strings;
  103. flen = statb.st_size;
  104. while (fgets_unlocked(cp, flen - (cp - strings), fp) != NULL) {
  105. while (*cp != '#' && *cp != '/' && *cp != '\0')
  106. cp++;
  107. if (*cp == '#' || *cp == '\0')
  108. continue;
  109. *sp++ = cp;
  110. while (!isspace(*cp) && *cp != '#' && *cp != '\0')
  111. cp++;
  112. *cp++ = '\0';
  113. }
  114. *sp = NULL;
  115. fclose(fp);
  116. return (shells);
  117. cleanup:
  118. __free_initshell_memory();
  119. fclose(fp);
  120. return (char **) validsh;
  121. }