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Diffstat (limited to 'examples/loadables/dirname.c')
-rw-r--r-- | examples/loadables/dirname.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/examples/loadables/dirname.c b/examples/loadables/dirname.c new file mode 100644 index 0000000..6159560 --- /dev/null +++ b/examples/loadables/dirname.c @@ -0,0 +1,95 @@ +/* dirname - return directory portion of pathname */ + +/* See Makefile for compilation details. */ + +#include "config.h" + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include <stdio.h> +#include "builtins.h" +#include "shell.h" + +dirname_builtin (list) + WORD_LIST *list; +{ + int slen; + char *string; + + if (list == 0 || list->next) + { + builtin_usage (); + return (EX_USAGE); + } + + if (no_options (list)) + return (EX_USAGE); + + string = list->word->word; + slen = strlen (string); + + /* Strip trailing slashes */ + while (slen > 0 && string[slen - 1] == '/') + slen--; + + /* (2) If string consists entirely of slash characters, string shall be + set to a single slash character. In this case, skip steps (3) + through (8). */ + if (slen == 0) + { + fputs ("/\n", stdout); + return (EXECUTION_SUCCESS); + } + + /* (3) If there are any trailing slash characters in string, they + shall be removed. */ + string[slen] = '\0'; + + /* (4) If there are no slash characters remaining in string, string + shall be set to a single period character. In this case, skip + steps (5) through (8). + + (5) If there are any trailing nonslash characters in string, + they shall be removed. */ + + while (--slen >= 0) + if (string[slen] == '/') + break; + + if (slen < 0) + { + fputs (".\n", stdout); + return (EXECUTION_SUCCESS); + } + + /* (7) If there are any trailing slash characters in string, they + shall be removed. */ + while (--slen >= 0) + if (string[slen] != '/') + break; + string[++slen] = '\0'; + + /* (8) If the remaining string is empty, string shall be set to a single + slash character. */ + printf ("%s\n", (slen == 0) ? "/" : string); + return (EXECUTION_SUCCESS); +} + +char *dirname_doc[] = { + "The STRING is converted to the name of the directory containing", + "the filename corresponding to the last pathname component in STRING.", + (char *)NULL +}; + +/* The standard structure describing a builtin command. bash keeps an array + of these structures. */ +struct builtin dirname_struct = { + "dirname", /* builtin name */ + dirname_builtin, /* function implementing the builtin */ + BUILTIN_ENABLED, /* initial flags for builtin */ + dirname_doc, /* array of long documentation strings. */ + "dirname string", /* usage synopsis */ + 0 /* reserved for internal use */ +}; |