Audit readlink(1)
1) Properly document e, f and m-flags in the manpage.
2) Clear up the code for the m-flag-handling. Add idiomatic
'/'-path-traversal as already seen in mkdir(1).
3) Unwrap the SWAP_BUF()-macro.
4) BUGFIX: Actually handle the f-flag properly. Only resolve
the dirname and append the basename later.
5) Use fputs() instead of printf("%s", ...).
This commit is contained in:
FRIGN
parent
e6c20fe367
commit
a531865fe5
2
README
2
README
|
|
@ -55,7 +55,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
|
|||
=*| printenv non-posix none
|
||||
#*| printf yes none
|
||||
=*| pwd yes none
|
||||
= readlink non-posix none
|
||||
=*| readlink non-posix none
|
||||
=*| renice yes none
|
||||
=*| rm yes none (-i)
|
||||
=*| rmdir yes none
|
||||
|
|
|
|||
31
readlink.1
31
readlink.1
|
|
@ -1,4 +1,4 @@
|
|||
.Dd January 31, 2015
|
||||
.Dd March 20, 2015
|
||||
.Dt READLINK 1
|
||||
.Os sbase
|
||||
.Sh NAME
|
||||
|
|
@ -6,30 +6,27 @@
|
|||
.Nd print symbolic link target or canonical file name
|
||||
.Sh SYNOPSIS
|
||||
.Nm
|
||||
.Op Fl fn
|
||||
.Ar name
|
||||
.Op Fl e | Fl f | Fl m
|
||||
.Op Fl n
|
||||
.Ar path
|
||||
.Sh DESCRIPTION
|
||||
If
|
||||
.Ar name
|
||||
is a symbolic link,
|
||||
.Nm
|
||||
writes its target to stdout.
|
||||
If
|
||||
.Fl f
|
||||
is not set and
|
||||
.Ar name
|
||||
is not a symbolic link,
|
||||
writes the target of
|
||||
.Ar path ,
|
||||
if it is a symbolic link, to stdout.
|
||||
If not,
|
||||
.Nm
|
||||
exits with a nonzero exit code without printing anything.
|
||||
exits with a non-zero return value.
|
||||
.Sh OPTIONS
|
||||
.Bl -tag -width Ds
|
||||
.It Fl f
|
||||
.It Fl e | Fl f | Fl m
|
||||
Canonicalize
|
||||
.Ar name ,
|
||||
which does not need to be a symlink,
|
||||
by recursively following every symlink in its components.
|
||||
which needn't be a symlink,
|
||||
by recursively following every symlink in its path components.
|
||||
All | All but the last | No path components must exist.
|
||||
.It Fl n
|
||||
Do not output the trailing newline.
|
||||
Do not print the terminating newline.
|
||||
.El
|
||||
.Sh SEE ALSO
|
||||
.Xr readlink 2 ,
|
||||
|
|
|
|||
55
readlink.c
55
readlink.c
|
|
@ -1,6 +1,7 @@
|
|||
/* See LICENSE file for copyright and license details. */
|
||||
#include <sys/stat.h>
|
||||
|
||||
#include <libgen.h>
|
||||
#include <unistd.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
|
|
@ -11,18 +12,17 @@
|
|||
static void
|
||||
usage(void)
|
||||
{
|
||||
eprintf("usage: %s [-efmn] name\n", argv0);
|
||||
eprintf("usage: %s [-e | -f | -m] [-n] path\n", argv0);
|
||||
}
|
||||
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
char buf1[PATH_MAX], buf2[PATH_MAX], arg[PATH_MAX];
|
||||
int nflag = 0;
|
||||
int mefflag = 0;
|
||||
ssize_t n;
|
||||
struct stat st;
|
||||
char *p = arg, *lp = NULL, *b = buf1;
|
||||
ssize_t n;
|
||||
int nflag = 0, mefflag = 0;
|
||||
char buf1[PATH_MAX], buf2[PATH_MAX], arg[PATH_MAX],
|
||||
*p, *slash, *prefix, *lp, *b = buf1;
|
||||
|
||||
ARGBEGIN {
|
||||
case 'm':
|
||||
|
|
@ -40,57 +40,54 @@ main(int argc, char *argv[])
|
|||
if (argc != 1)
|
||||
usage();
|
||||
|
||||
if (strlen(argv[0]) > PATH_MAX - 1)
|
||||
if (strlen(argv[0]) >= PATH_MAX)
|
||||
eprintf("path too long\n");
|
||||
|
||||
#define SWAP_BUF() (b = (b == buf1 ? buf2 : buf1));
|
||||
switch (mefflag) {
|
||||
case 'm':
|
||||
if (argv[0][0] == '/') { /* case when path is on '/' */
|
||||
arg[0] = '/';
|
||||
arg[1] = '\0';
|
||||
p++;
|
||||
} else if (!strchr(argv[0], '/')) { /* relative path */
|
||||
arg[0] = '.';
|
||||
arg[1] = '/';
|
||||
arg[2] = '\0';
|
||||
} else
|
||||
arg[0] = '\0';
|
||||
slash = strchr(argv[0], '/');
|
||||
prefix = (slash == argv[0]) ? "/" : (!slash) ? "./" : "";
|
||||
|
||||
estrlcpy(arg, prefix, sizeof(arg));
|
||||
estrlcat(arg, argv[0], sizeof(arg));
|
||||
while ((p = strchr(p, '/'))) {
|
||||
|
||||
for (lp = "", p = arg + (argv[0][0] == '/'); *p; p++) {
|
||||
if (*p != '/')
|
||||
continue;
|
||||
*p = '\0';
|
||||
if (!realpath(arg, b)) {
|
||||
*p = '/';
|
||||
goto mdone;
|
||||
}
|
||||
SWAP_BUF();
|
||||
b = (b == buf1) ? buf2 : buf1;
|
||||
lp = p;
|
||||
*p++ = '/';
|
||||
*p = '/';
|
||||
}
|
||||
if (!realpath(arg, b)) {
|
||||
mdone:
|
||||
SWAP_BUF();
|
||||
if (lp) {
|
||||
/* drop the extra '/' on root */
|
||||
lp += (argv[0][0] == '/' &&
|
||||
lp - arg == 1);
|
||||
b = (b == buf1) ? buf2 : buf1;
|
||||
estrlcat(b, lp, sizeof(arg));
|
||||
}
|
||||
}
|
||||
break;
|
||||
case 'e':
|
||||
if (stat(argv[0], &st) < 0)
|
||||
eprintf("stat %s:", argv[0]);
|
||||
case 'f': /* fallthrough */
|
||||
if (!realpath(argv[0], b))
|
||||
eprintf("realpath %s:", argv[0]);
|
||||
break;
|
||||
case 'f':
|
||||
p = dirname(estrdup(argv[0]));
|
||||
if (!realpath(p, b))
|
||||
eprintf("realpath %s:", p);
|
||||
estrlcat(b, "/", sizeof(arg));
|
||||
estrlcat(b, basename(estrdup(argv[0])), sizeof(arg));
|
||||
break;
|
||||
default:
|
||||
if ((n = readlink(argv[0], b, PATH_MAX - 1)) < 0)
|
||||
eprintf("readlink %s:", argv[0]);
|
||||
b[n] = '\0';
|
||||
}
|
||||
printf("%s", b);
|
||||
fputs(b, stdout);
|
||||
if (!nflag)
|
||||
putchar('\n');
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user