Date: Fri, 3 Jan 2003 02:25:34 +0100 From: Paul Schenkeveld <fb-hackers@psconsult.nl> To: Tim Kientzle <kientzle@acm.org> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Reading rc.conf from C programs? Message-ID: <20030103022534.A11923@psconsult.nl> In-Reply-To: <3E14C866.1040306@acm.org>; from kientzle@acm.org on Thu, Jan 02, 2003 at 03:16:54PM -0800 References: <1041540674.3e14a642d30b5@webmail1.isg.siue.edu> <4967.1041540976@critter.freebsd.dk> <20030102230154.A8638@psconsult.nl> <3E14C866.1040306@acm.org>
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On Thu, Jan 02, 2003 at 03:16:54PM -0800, Tim Kientzle wrote:
> Paul Schenkeveld wrote:
>
> > If people think that -q is a good option for printenv, I can come up
> > with a patch for the standard printenv. Opinions?
>
>
> Some form of unambiguous output from printenv
> would be nice. I would suggest quoting both the
> variable name and the value just to be on the safe side.
>
> Even better: modify 'env' to support
> that format as input. Then you could
> use, e.g.,
> printenv -q >saved_environment
> to record the environment and then use
> env - -r saved_environment <command>
> to recreate that environment.
I've rolled a patch for a recent -STABLE printenv (see below).
Comments? Anyone care to commit this?
Will see if I can do a patch for env over the weekend.
--
Paul Schenkeveld, Consultant
PSconsult ICT Services BV
--- /usr/src/usr.bin/printenv/printenv.1 Wed Jun 26 10:25:30 2002
+++ src/printenv/printenv.1 Fri Jan 3 02:14:11 2003
@@ -42,6 +42,9 @@
.Nd print out the environment, set and print environment
.Sh SYNOPSIS
.Nm
+.Op Fl e
+.Op Fl q
+.Op Fl Q
.Op Ar name
.Nm env
.Op Fl
@@ -81,6 +84,17 @@
.Pp
The options are as follows:
.Bl -tag -width indent
+.It Fl e
+Output
+.Nm export
+commands for every environment variable.
+.It Fl q
+Double quote the value of every environment variable,
+special characters ("\\`$) will be preceeded bay a backslash.
+.It Fl Q
+Like
+.Fl q
+but also quote the name of the variable.
.It Fl i
Execute the
.Ar utility
--- /usr/src/usr.bin/printenv/printenv.c Sat Mar 29 05:31:36 1997
+++ src/printenv/printenv.c Fri Jan 3 02:18:32 2003
@@ -49,6 +49,8 @@
#include <unistd.h>
void usage __P((void));
+void print_var __P((char *, int));
+void print_quoted __P((char *));
/*
* printenv
@@ -62,12 +64,25 @@
char *argv[];
{
extern char **environ;
- register char *cp, **ep;
+ register char *cp, **ep, *eq;
register size_t len;
int ch;
+ int flags = 0;
+#define eFLAG 1
+#define qFLAG 2
+#define QFLAG 4
- while ((ch = getopt(argc, argv, "")) != -1)
+ while ((ch = getopt(argc, argv, "eqQ")) != -1)
switch(ch) {
+ case 'e':
+ flags |= eFLAG;
+ break;
+ case 'q':
+ flags |= qFLAG;
+ break;
+ case 'Q':
+ flags |= qFLAG | QFLAG;
+ break;
case '?':
default:
usage();
@@ -76,8 +91,18 @@
argv += optind;
if (argc == 0) {
- for (ep = environ; *ep; ep++)
- (void)printf("%s\n", *ep);
+ for (ep = environ; *ep; ep++) {
+ if (flags & eFLAG) {
+ for (eq = *ep; *eq && *eq != '='; )
+ eq++;
+ printf("export %s%.*s%s; ",
+ flags & QFLAG ? "\"" : "",
+ eq - *ep,
+ *ep,
+ flags & QFLAG ? "\"" : "");
+ }
+ print_var(*ep, flags);
+ }
exit(0);
}
len = strlen(*argv);
@@ -85,7 +110,12 @@
if (!memcmp(*ep, *argv, len)) {
cp = *ep + len;
if (!*cp || *cp == '=') {
- (void)printf("%s\n", *cp ? cp + 1 : cp);
+ if (flags & qFLAG) {
+ print_quoted(*ep);
+ putchar('\n');
+ }
+ else
+ (void)printf("%s\n", *cp ? cp + 1 : cp);
exit(0);
}
}
@@ -93,8 +123,50 @@
}
void
+print_var(var, flags)
+ char *var;
+ int flags;
+{
+ register char *eq;
+ for (eq = var; eq && *eq && *eq != '='; )
+ eq++;
+ if (*eq == '=') {
+ *eq++ = '\0';
+ if (flags & QFLAG)
+ print_quoted(var);
+ else
+ printf("%s", var);
+ putchar('=');
+ if (flags & qFLAG)
+ print_quoted(eq);
+ else
+ printf("%s", eq);
+ putchar('\n');
+ }
+}
+
+void
+print_quoted(str)
+ char *str;
+{
+ putchar('"');
+ for ( ; *str; str++)
+ switch (*str) {
+ case '\\':
+ case '"':
+ case '`':
+ case '$':
+ putchar('\\');
+ /* FALL THRU */
+ default:
+ putchar(*str);
+ }
+ putchar('"');
+}
+
+void
usage()
{
- (void)fprintf(stderr, "usage: printenv [name]\n");
+ (void)fprintf(stderr, "usage: printenv [-eqQ] [name]\n");
exit(1);
}
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