add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/elvis/ref.c

@@ -0,0 +1,131 @@
+/* ref.c */
+
+/* Author:
+ *	Steve Kirkendall
+ *	16820 SW Tallac Way
+ *	Beaverton, OR 97006
+ *	kirkenda@jove.cs.pdx.edu, or ...uunet!tektronix!psueea!jove!kirkenda
+ */
+
+
+/* This program looks up the declarations of library functions. */
+
+#include <stdio.h>
+
+/* This is the list of files that are searched. */
+char *refslist[] = {
+	"refs",
+	"/usr/src/lib/refs",
+	"../lib/refs",
+	"/usr/local/lib/refs",
+};
+#define NREFS	(sizeof refslist / sizeof(char *))
+
+main(argc, argv)
+	int	argc;
+	char	**argv;
+{
+	int	i;	/* used to step through the refslist */
+
+	/* make sure our arguments are OK */
+	if (argc != 2)
+	{
+		fprintf(stderr, "usage: %s function_name\n", *argv);
+		exit(2);
+	}
+
+	/* check for the function in each database */
+	for (i = 0; i < NREFS; i++)
+	{
+		if (lookinfor(refslist[i], argv[1]))
+		{
+			exit(0);
+		}
+	}
+
+	fprintf(stderr, "%s: don't know about %s\n", argv[0], argv[1]);
+	exit(2);
+}
+
+
+/* This function checks a single file for the function.  Returns 1 if found */
+int lookinfor(filename, func)
+	char	*filename;	/* name of file to look in */
+	char	*func;		/* name of function to look for */
+{
+	FILE	*fp;	/* stream used to access the database */
+	char	linebuf[300];
+		/* NOTE: in actual use, the first character of linebuf is */
+		/* set to ' ' and then we use all EXCEPT the 1st character */
+		/* everywhere in this function.  This is because the func */
+		/* which examines the linebuf could, in some circumstances */
+		/* examine the character before the used part of linebuf; */
+		/* we need to control what happens then.		   */
+
+
+	/* open the database file */
+	fp = fopen(filename, "r");
+	if (!fp)
+	{
+		return 0;
+	}
+
+	/* find the desired entry */
+	*linebuf = ' ';
+	do
+	{
+		if (!fgets(linebuf + 1, (sizeof linebuf) - 1, fp))
+		{
+			fclose(fp);
+			return 0;
+		}
+	} while (!desired(linebuf + 1, func));
+
+	/* print it */
+	do
+	{
+		fputs(linebuf + 1, stdout);
+	} while (fgets(linebuf + 1, sizeof linebuf, fp) && linebuf[1] == '\t');
+
+	/* cleanup & exit */
+	fclose(fp);
+	return 1;
+}
+
+
+/* This function checks to see if a given line is the first line of the */
+/* entry the user wants to see.  If it is, return non-0 else return 0   */
+desired(line, word)
+	char	*line;	/* the line buffer */
+	char	*word;	/* the string it should contain */
+{
+	static	wlen = -1;/* length of the "word" variable's value */
+	register char *scan;
+
+	/* if this line starts with a tab, it couldn't be desired */
+	if (*line == '\t')
+	{
+		return 0;
+	}
+
+	/* if we haven't found word's length yet, do so */
+	if (wlen < 0)
+	{
+		wlen = strlen(word);
+	}
+
+	/* search for the word in the line */
+	for (scan = line; *scan != '('; scan++)
+	{
+	}
+	while (*--scan == ' ')
+	{
+	}
+	scan -= wlen;
+	if (scan < line - 1 || *scan != ' ' && *scan != '\t' && *scan != '*')
+	{
+		return 0;
+	}
+	scan++;
+	return !strncmp(scan, word, wlen);
+}