Added routines to read the canonical UNIX configuration file. This will

later be applied to a number of programs (inetd for instance) to clean
out the bogus code doing the same thing, modulus all the bugs.

If you need to read a '#'-is-a-comment-file, please use these routines.

I realize that the shlib# should be bumped (for the non-US world:
increased by something), but will defer this until something significant
happens.

3 files changed, 267 insertions, 4 deletions

diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index e307157bad42..c9cf4e7656a8 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -1,11 +1,11 @@
 #	From: @(#)Makefile.inc	8.3 (Berkeley) 4/16/94
-#	$Id: Makefile.inc,v 1.12 1994/09/25 01:38:27 wollman Exp $
+#	$Id: Makefile.inc,v 1.13 1994/10/25 14:04:32 bde Exp $
 
 # machine-independent gen sources
 .PATH: ${.CURDIR}/${MACHINE}/gen ${.CURDIR}/gen
 
-SRCS+=	alarm.c assert.c clock.c closedir.c confstr.c crypt.c ctermid.c \
-	daemon.c devname.c disklabel.c err.c errlst.c \
+SRCS+=	alarm.c assert.c clock.c closedir.c config.c confstr.c crypt.c \
+	ctermid.c daemon.c devname.c disklabel.c err.c errlst.c \
 	exec.c fnmatch.c frexp.c fstab.c fts.c getbootfile.c getbsize.c \
 	getcap.c getcwd.c getdomainname.c getgrent.c getgrouplist.c \
 	gethostname.c getloadavg.c getlogin.c getmntinfo.c getnetgrent.c \
@@ -36,7 +36,8 @@ errlst.o errlst.po:
 	rm -f errlst.s
 .endif
 
-MAN3+=	gen/alarm.3 gen/clock.3 gen/confstr.3 gen/crypt.3 gen/ctermid.3 \
+MAN3+=	gen/alarm.3 gen/clock.3 gen/confstr.3 gen/config_open.3 \
+	gen/crypt.3 gen/ctermid.3 \
 	gen/daemon.3 gen/devname.3 gen/directory.3 gen/err.3 gen/exec.3 \
 	gen/fnmatch.3 gen/frexp.3 gen/fts.3 gen/getbsize.3 gen/getbootfile.3 \
 	gen/getcap.3 gen/getcwd.3 gen/getdiskbyname.3 gen/getfsent.3 \
@@ -53,6 +54,8 @@ MAN3+=	gen/alarm.3 gen/clock.3 gen/confstr.3 gen/crypt.3 gen/ctermid.3 \
 	gen/times.3 gen/timezone.3 gen/ttyname.3 gen/tzset.3 gen/ualarm.3 \
 	gen/uname.3 gen/unvis.3 gen/usleep.3 gen/utime.3 gen/valloc.3 gen/vis.3
 
+MLINKS+=config_open.3 config_next.3 config_open.3 config_close.3 \
+	config_open.3 config_skip.3 
 MLINKS+=crypt.3 encrypt.3 crypt.3 setkey.3
 MLINKS+=directory.3 closedir.3 directory.3 dirfd.3 directory.3 opendir.3 \
 	directory.3 readdir.3 directory.3 rewinddir.3 directory.3 seekdir.3 \
diff --git a/lib/libc/gen/config.c b/lib/libc/gen/config.c
new file mode 100644
index 000000000000..6ea292b78b13
--- /dev/null
+++ b/lib/libc/gen/config.c
@@ -0,0 +1,187 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * $Id$
+ *
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$Id: config.c,v 1.1 1994/01/14 12:24:39 jkh Exp $";
+#endif				/* LIBC_SCCS and not lint */
+
+/*
+ * This file contains four procedures used to read config-files.
+ *
+ * char * config_open(const char *filename,int contlines)
+ *	Will open the named file, read it into a private malloc'ed area,
+ *	and close the file again.
+ *	All lines where the first !isspace() char is '#' are deleted.
+ *	If contlines are non-zero lines where the first char is isspace() 
+ *	will be joined to the preceeding line.
+ *	In case of trouble the name of the offending system call will be
+ *	returned.  On success NULL is returned.
+ *
+ * void   config_close()
+ *	This will free the internal malloc'ed area.
+ *
+ * char * config_next()
+ *	This will return a pointer to the next entry in the area.  NULL is
+ *	returned at "end of file".  The return value is '\0' terminated, and
+ *	can be modified, but the contents must be copied somewhere else for
+ *	permanent use.
+ *
+ * char * config_skip(char **p)
+ *	This will pick out the next word from the string.  The return-value
+ *	points to the word found, and *p is advanced past the word.  NULL is
+ *	returned at "end of string".
+ *
+ * Many programs have a n*100 bytes config-file and N*1000 bytes of source
+ * to read it.  Doing pointer-aerobics on files that small is a waste of
+ * time, and bashing around with getchar/ungetc isn't much better.  These
+ * routines implement a simple algorithm and syntax.
+ *
+ * config_skip consider a contiguous string of !isspace() chars a word.
+ *
+ * 13nov1994 Poul-Henning Kamp  phk@login.dknet.dk
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <string.h>
+
+static char *file_buf;
+static char *ptr;
+
+char   *
+config_open(const char *filename, int contlines)
+{
+	int     fd;
+	struct stat st;
+	char   *p, *q;
+
+	if ((fd = open(filename, O_RDONLY)) < 0)
+		return "open";
+	if (fstat(fd, &st) < 0) {
+		close(fd);
+		return "fstat";
+	}
+	if (file_buf)
+		free(file_buf);
+	file_buf = malloc(st.st_size + 2);
+	if (!file_buf) {
+		close(fd);
+		return "malloc";
+	}
+	if (st.st_size != read(fd, file_buf, st.st_size)) {
+		free(file_buf);
+		file_buf = (char *) 0;
+		close(fd);
+		return "read";
+	}
+	close(fd);
+	file_buf[st.st_size] = '\n';
+	file_buf[st.st_size + 1] = '\0';
+
+	/*
+         * /^[ \t]*#[^\n]*$/d
+	 * 
+	 * Delete all lines where the first !isspace() char is '#' 
+         */
+
+	ptr = file_buf;
+	for (p = ptr; *p;) {
+		for (q = p; *q != '\n' && isspace(*q); q++)
+			continue;
+		if (*q == '#') {
+			p = strchr(p, '\n');
+			if (p)
+				p++;
+		} else {
+			q = strchr(p, '\n');
+			q++;
+			memcpy(ptr, p, q - p);
+			ptr += q - p;
+			p = q;
+		}
+	}
+	*ptr = '\0';
+	ptr = file_buf;
+
+	if (!contlines)
+		return 0;
+
+	/* Join all lines starting with a isspace() char to the preceeding
+	 * line */
+
+	for (p = ptr; *p;) {
+		q = strchr(p, '\n');
+		if (isspace(*(q + 1)))
+			*q = ' ';
+		p = q + 1;
+	}
+
+	return 0;
+}
+
+void
+config_close(void)
+{
+	if (file_buf)
+		free(file_buf);
+	ptr = file_buf = 0;
+}
+
+/*
+ * Get next entry.  config_open did all the weird stuff, so just return
+ * the next line.
+ */
+
+char   *
+config_next(void)
+{
+	char   *p;
+
+	/* We might be done already ! */
+	if (!ptr || !*ptr)
+		return 0;
+
+	while (isspace(*ptr))
+	    ptr++;
+	p = ptr;
+	ptr = strchr(p, '\n');
+	if (ptr) {
+		*ptr = '\0';
+		ptr++;
+	}
+	return p;
+}
+
+/*
+ * Return next word
+ */
+
+char   *
+config_skip(char **p)
+{
+	char   *q, *r;
+
+	if (!*p || !**p)
+		return 0;
+	for (q = *p; isspace(*q); q++);
+	if (!*q)
+		return 0;
+	for (r = q; *r && !isspace(*r); r++);
+	if (*r)
+		*r++ = '\0';
+	*p = r;
+	return q;
+}
diff --git a/lib/libc/gen/config_open.3 b/lib/libc/gen/config_open.3
new file mode 100644
index 000000000000..f51bc6cd01f8
--- /dev/null
+++ b/lib/libc/gen/config_open.3
@@ -0,0 +1,73 @@
+.\" ----------------------------------------------------------------------------
+.\" "THE BEER-WARE LICENSE" (Revision 42):
+.\" <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
+.\" can do whatever you want with this stuff. If we meet some day, and you think
+.\" this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+.\" ----------------------------------------------------------------------------
+.\" 
+.\"  $Id$
+.\" 
+.Dd November 13, 1994
+.Dt config_open 3
+.Os FreeBSD
+.Sh NAME
+.Nm config_open ,
+.Nm config_close ,
+.Nm config_next ,
+.Nm config_skip
+.Nd read config files
+.Sh SYNOPSIS
+.Ft char *
+.Fn config_open "const char *filename" "int contlines"
+.Ft void
+.Fn config_close
+.Ft char *
+.Fn config_next
+.Ft char *
+.Fn config_skip "char **string"
+.Sh DESCRIPTION
+These functions are used to read config files with the following syntax:
+.Bl -bullet -compact
+.It
+All lines where the first
+.Sq !isspace()
+is '#' are comments which are discarded.
+.It
+If continuation-lines are enabled, any line starting with a 
+.Sq isspace()
+character is joined to the preceeding line and blank lines are discarded.
+.It
+An entry starts at the first 
+.Sq !isspace()
+character and ends at the first 
+.Sq Li \en
+.Li .
+.El
+.Pp
+.Fn config_open
+will open the specified
+.Fa filename
+and read it into a private malloced area, and close the file again. If
+.Fa contlines
+is non-zero, continuation lines will be allowed.
+In case of trouble, the name of the system-call causing the trouble will
+be returned. If successful,
+.Fn config_open
+returns NULL.
+.Pp
+.Fn config_close
+will free the malloced area.
+.Pp
+.Fn config_next
+returns the next entry in the area. NULL is returned to indicate End-of-file.
+The returned string is null-terminated.
+.Pp
+.Fn config_skip
+returns the next word from the string
+.Fa *string
+.Li .
+.Fa *string
+will be advanced to point to the next word.
+NULL is returned to indicate the end of the string.
+.Sh AUTHOR
+Poul-Henning Kamp <phk@login.dknet.dk>