sbase/printenv.c

/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <stdlib.h>

#include "util.h"

extern char **environ;

int
main(int argc, char *argv[])
{
	char *var;
	int ret = 0;

	argv0 = *argv, argv0 ? (argc--, argv++) : (void *)0;

	if (!argc) {
		for (; *environ; environ++)
			puts(*environ);
	} else {
		for (; *argv; argc--, argv++) {
			if ((var = getenv(*argv)))
				puts(var);
			else
				ret = 1;
		}
	}

	return fshut(stdout, "<stdout>") ? 2 : ret;
}
Add license file details at top of files 2013-10-07 12:03:26 -04:00			`/* See LICENSE file for copyright and license details. */`
Adding the new C files too. 2013-06-09 09:20:55 -04:00			`#include <stdio.h>`
			`#include <stdlib.h>`
Fix coding style It was about damn time. Consistency is very important in such a big codebase. 2014-11-13 12:29:30 -05:00
Use arg.h as much as possible and add usage() where missing Rename eusage() to usage() as well. 2013-10-07 12:13:01 -04:00			`#include "util.h"`
Adding the new C files too. 2013-06-09 09:20:55 -04:00
			`extern char **environ;`

			`int`
Fix char *argv to char argv[] 2014-04-18 06:51:18 -04:00			`main(int argc, char *argv[])`
Adding the new C files too. 2013-06-09 09:20:55 -04:00			`{`
			`char *var;`
Set exit status accordingly in printenv(1) 2014-11-16 08:13:31 -05:00			`int ret = 0;`
Adding the new C files too. 2013-06-09 09:20:55 -04:00
Handle { NULL } argv[] properly in manual arg-reduction Thanks izabera for reporting this! 2017-08-05 17:50:39 -04:00			`argv0 = argv, argv0 ? (argc--, argv++) : (void )0;`
Use arg.h as much as possible and add usage() where missing Rename eusage() to usage() as well. 2013-10-07 12:13:01 -04:00
Audit printenv(1) 1) argc style 2) safeguard argv-loop as already seen in echo(1) with argc-decrement. 2015-02-28 15:47:17 -05:00			`if (!argc) {`
Make already audited tools argv-centric instead of argc-centric This has already been suggested by Evan Gates <evan.gates@gmail.com> and he's totally right about it. So, what's the problem? I wrote a testing program asshole.c with int main(void) { execl("/path/to/sbase/echo", "echo", "test"); return 0; } and checked the results with glibc and musl. Note that the sentinel NULL is missing from the end of the argument list. glibc calculates an argc of 5, musl 4 (instead of 2) and thus mess up things anyway. The powerful arg.h also focuses on argv instead of argc as well, but ignoring argc completely is also the wrong way to go. Instead, a more idiomatic approach is to check *argv only and decrement argc on the go. While at it, I rewrote yes(1) in an argv-centric way as well. All audited tools have been "fixed" and each following audited tool will receive the same treatment. 2015-03-02 08:19:26 -05:00			`for (; *environ; environ++)`
			`puts(*environ);`
Fix completely broken printenv(1) 2014-11-16 08:11:12 -05:00			`} else {`
Make already audited tools argv-centric instead of argc-centric This has already been suggested by Evan Gates <evan.gates@gmail.com> and he's totally right about it. So, what's the problem? I wrote a testing program asshole.c with int main(void) { execl("/path/to/sbase/echo", "echo", "test"); return 0; } and checked the results with glibc and musl. Note that the sentinel NULL is missing from the end of the argument list. glibc calculates an argc of 5, musl 4 (instead of 2) and thus mess up things anyway. The powerful arg.h also focuses on argv instead of argc as well, but ignoring argc completely is also the wrong way to go. Instead, a more idiomatic approach is to check *argv only and decrement argc on the go. While at it, I rewrote yes(1) in an argv-centric way as well. All audited tools have been "fixed" and each following audited tool will receive the same treatment. 2015-03-02 08:19:26 -05:00			`for (; *argv; argc--, argv++) {`
Audit printenv(1) 1) argc style 2) safeguard argv-loop as already seen in echo(1) with argc-decrement. 2015-02-28 15:47:17 -05:00			`if ((var = getenv(*argv)))`
Make already audited tools argv-centric instead of argc-centric This has already been suggested by Evan Gates <evan.gates@gmail.com> and he's totally right about it. So, what's the problem? I wrote a testing program asshole.c with int main(void) { execl("/path/to/sbase/echo", "echo", "test"); return 0; } and checked the results with glibc and musl. Note that the sentinel NULL is missing from the end of the argument list. glibc calculates an argc of 5, musl 4 (instead of 2) and thus mess up things anyway. The powerful arg.h also focuses on argv instead of argc as well, but ignoring argc completely is also the wrong way to go. Instead, a more idiomatic approach is to check *argv only and decrement argc on the go. While at it, I rewrote yes(1) in an argv-centric way as well. All audited tools have been "fixed" and each following audited tool will receive the same treatment. 2015-03-02 08:19:26 -05:00			`puts(var);`
Set exit status accordingly in printenv(1) 2014-11-16 08:13:31 -05:00			`else`
			`ret = 1;`
Fix completely broken printenv(1) 2014-11-16 08:11:12 -05:00			`}`
Adding the new C files too. 2013-06-09 09:20:55 -04:00			`}`
Audit printenv(1) 1) argc style 2) safeguard argv-loop as already seen in echo(1) with argc-decrement. 2015-02-28 15:47:17 -05:00
printenv: exit status is 2 on failure This provides a reliable and portable way to test whether an environment variable is defined. (Of course, if you are using glibc you may get false positives if you include a = in the query.) Signed-off-by: Mattias Andrée <maandree@kth.se> 2016-03-29 19:16:27 -04:00			`return fshut(stdout, "<stdout>") ? 2 : ret;`
Adding the new C files too. 2013-06-09 09:20:55 -04:00			`}`