getconf.c revision 7c2fbfb345896881c631598ee3852ce9ce33fb07
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1992-2008 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* getconf - get configuration values
*/
static const char usage[] =
"[-?\n@(#)$Id: getconf (AT&T Research) 2008-04-24 $\n]"
USAGE_LICENSE
"[+NAME?getconf - get configuration values]"
"[+DESCRIPTION?\bgetconf\b displays the system configuration value for"
" \aname\a. If \aname\a is a filesystem specific variable then"
" the value is determined relative to \apath\a or the current"
" directory if \apath\a is omitted. If \avalue\a is specified then"
" \bgetconf\b attempts to change the process local value to \avalue\a."
" \b-\b may be used in place of \apath\a when it is not relevant."
" If \apath\a is \b=\b then the the \avalue\a is cached and used"
" for subsequent tests in the calling and all child processes."
" Only \bwritable\b variables may be set; \breadonly\b variables"
" cannot be changed.]"
"[+?The current value for \aname\a is written to the standard output. If"
" \aname\a is valid but undefined then \bundefined\b is written to"
" the standard output. If \aname\a is invalid or an error occurs in"
" determining its value, then a diagnostic written to the standard error"
" and \bgetconf\b exits with a non-zero exit status.]"
"[+?More than one variable may be set or queried by providing the \aname\a"
" \apath\a \avalue\a 3-tuple for each variable, specifying \b-\b for"
" \avalue\a when querying.]"
"[+?If no operands are specified then all known variables are written in"
" \aname\a=\avalue\a form to the standard output, one per line."
" Only one of \b--call\b, \b--name\b or \b--standard\b may be specified.]"
"[+?This implementation uses the \bastgetconf\b(3) string interface to the native"
" \bsysconf\b(2), \bconfstr\b(2), \bpathconf\b(2), and \bsysinfo\b(2)"
" system calls. If \bgetconf\b on \b$PATH\b is not the default native"
" \bgetconf\b, named by \b$(getconf GETCONF)\b, then \bastgetconf\b(3)"
" checks only \bast\b specific extensions and the native system calls;"
" invalid options and/or names not supported by \bastgetconf\b(3) cause"
" the \bgetconf\b on \b$PATH\b to be executed.]"
"[a:all?Call the native \bgetconf\b(1) with option \b-a\b.]"
"[b:base?List base variable name sans call and standard prefixes.]"
"[c:call?Display variables with call prefix that matches \aRE\a. The call"
" prefixes are:]:[RE]{"
" [+CS?\bconfstr\b(2)]"
" [+PC?\bpathconf\b(2)]"
" [+SC?\bsysconf\b(2)]"
" [+SI?\bsysinfo\b(2)]"
" [+XX?Constant value.]"
"}"
"[d:defined?Only display defined values when no operands are specified.]"
"[l:lowercase?List variable names in lower case.]"
"[n:name?Display variables with name that match \aRE\a.]:[RE]"
"[p:portable?Display the named \bwritable\b variables and values in a form that"
" can be directly executed by \bsh\b(1) to set the values. If \aname\a"
" is omitted then all \bwritable\b variables are listed.]"
"[q:quote?\"...\" quote values.]"
"[r:readonly?Display the named \breadonly\b variables in \aname\a=\avalue\a form."
" If \aname\a is omitted then all \breadonly\b variables are listed.]"
"[s:standard?Display variables with standard prefix that matches \aRE\a."
" Use the \b--table\b option to view all standard prefixes, including"
" local additions. The standard prefixes available on all systems"
" are:]:[RE]{"
" [+AES]"
" [+AST]"
" [+C]"
" [+GNU]"
" [+POSIX]"
" [+SVID]"
" [+XBS5]"
" [+XOPEN]"
" [+XPG]"
"}"
"[t:table?Display the internal table that contains the name, standard,"
" standard section, and system call symbol prefix for each variable.]"
"[w:writable?Display the named \bwritable\b variables in \aname\a=\avalue\a"
" form. If \aname\a is omitted then all \bwritable\b variables are"
" listed.]"
"[v:specification?Call the native \bgetconf\b(1) with option"
" \b-v\b \aname\a.]:[name]"
"\n"
"\n[ name [ path [ value ] ] ... ]\n"
"\n"
"[+ENVIRONMENT]{"
" [+_AST_FEATURES?Process local writable values that are different from"
" the default are stored in the \b_AST_FEATURES\b environment"
" variable. The \b_AST_FEATURES\b value is a space-separated"
" list of \aname\a \apath\a \avalue\a 3-tuples, where"
" \aname\a is the system configuration name, \apath\a is the"
" corresponding path, \b-\b if no path is applicable, and"
" \avalue\a is the system configuration value.]"
"}"
"[+SEE ALSO?\bpathchk\b(1), \bconfstr\b(2), \bpathconf\b(2),"
" \bsysconf\b(2), \bastgetconf\b(3)]"
;
#include <cmd.h>
#include <proc.h>
#include <ls.h>
typedef struct Path_s
{
const char* path;
int len;
} Path_t;
int
b_getconf(int argc, char** argv, void* context)
{
register char* name;
register char* path;
register char* value;
register const char* s;
register const char* t;
char* pattern;
char* native;
char* cmd;
Path_t* e;
Path_t* p;
int flags;
int n;
int i;
int m;
int q;
char** oargv;
char buf[PATH_MAX];
Path_t std[64];
struct stat st0;
struct stat st1;
static const char empty[] = "-";
static const Path_t equiv[] = { { "/bin", 4 }, { "/usr/bin", 8 } };
cmdinit(argc, argv, context, ERROR_CATALOG, 0);
oargv = argv;
if (*(native = astconf("GETCONF", NiL, NiL)) != '/')
native = 0;
flags = 0;
name = 0;
pattern = 0;
for (;;)
{
switch (optget(argv, usage))
{
case 'a':
if (native)
goto defer;
continue;
case 'b':
flags |= ASTCONF_base;
continue;
case 'c':
flags |= ASTCONF_matchcall;
pattern = opt_info.arg;
continue;
case 'd':
flags |= ASTCONF_defined;
continue;
case 'l':
flags |= ASTCONF_lower;
continue;
case 'n':
flags |= ASTCONF_matchname;
pattern = opt_info.arg;
continue;
case 'p':
flags |= ASTCONF_parse;
continue;
case 'q':
flags |= ASTCONF_quote;
continue;
case 'r':
flags |= ASTCONF_read;
continue;
case 's':
flags |= ASTCONF_matchstandard;
pattern = opt_info.arg;
continue;
case 't':
flags |= ASTCONF_table;
continue;
case 'v':
if (native)
goto defer;
continue;
case 'w':
flags |= ASTCONF_write;
continue;
case ':':
if (native)
goto defer;
error(2, "%s", opt_info.arg);
break;
case '?':
error(ERROR_usage(2), "%s", opt_info.arg);
break;
}
break;
}
argv += opt_info.index;
if (!(name = *argv))
path = 0;
else if (streq(name, empty))
{
name = 0;
if (path = *++argv)
{
argv++;
if (streq(path, empty))
path = 0;
}
}
if (error_info.errors || !name && *argv)
error(ERROR_usage(2), "%s", optusage(NiL));
if (!name)
astconflist(sfstdout, path, flags, pattern);
else
{
flags = native ? (ASTCONF_system|ASTCONF_error) : 0;
do
{
if (!(path = *++argv))
value = 0;
else
{
if (streq(path, empty))
{
path = 0;
flags = 0;
}
if ((value = *++argv) && (streq(value, empty)))
{
value = 0;
flags = 0;
}
}
s = astgetconf(name, path, value, flags, errorf);
if (error_info.errors)
break;
if (!s)
goto defer;
if (!value)
{
if (flags & ASTCONF_write)
{
sfputr(sfstdout, name, ' ');
sfputr(sfstdout, path ? path : empty, ' ');
}
sfputr(sfstdout, s, '\n');
}
} while (*argv && (name = *++argv));
}
return error_info.errors != 0;
defer:
/*
* defer to argv[0] if absolute and it exists
*/
if ((cmd = oargv[0]) && *cmd == '/' && !access(cmd, X_OK))
goto found;
/*
* defer to the first getconf on $PATH that is also on the standard PATH
*/
e = std;
s = astconf("PATH", NiL, NiL);
q = !stat(equiv[0].path, &st0) && !stat(equiv[1].path, &st1) && st0.st_ino == st1.st_ino && st0.st_dev == st1.st_dev;
m = 0;
do
{
for (t = s; *s && *s != ':'; s++);
if ((n = s - t) && *t == '/')
{
if (q)
for (i = 0; i < 2; i++)
if (n == equiv[i].len && !strncmp(t, equiv[i].path, n))
{
if (m & (i+1))
t = 0;
else
{
m |= (i+1);
if (!(m & (!i+1)))
{
m |= (!i+1);
e->path = t;
e->len = n;
e++;
if (e >= &std[elementsof(std)])
break;
t = equiv[!i].path;
n = equiv[!i].len;
}
}
}
if (t)
{
e->path = t;
e->len = n;
e++;
}
}
while (*s == ':')
s++;
} while (*s && e < &std[elementsof(std)]);
if (e < &std[elementsof(std)])
{
e->len = strlen(e->path = "/usr/sbin");
if (++e < &std[elementsof(std)])
{
e->len = strlen(e->path = "/sbin");
e++;
}
}
if (s = getenv("PATH"))
do
{
for (t = s; *s && *s != ':'; s++);
if ((n = s - t) && *t == '/')
{
for (p = std; p < e; p++)
if (p->len == n && !strncmp(t, p->path, n))
{
sfsprintf(buf, sizeof(buf), "%-*.*s/%s", n, n, t, error_info.id);
if (!access(buf, X_OK))
{
cmd = buf;
goto found;
}
}
}
while (*s == ':')
s++;
} while (*s);
/*
* defer to the first getconf on the standard PATH
*/
for (p = std; p < e; p++)
{
sfsprintf(buf, sizeof(buf), "%-*.*s/%s", p->len, p->len, p->path, error_info.id);
if (!access(buf, X_OK))
{
cmd = buf;
goto found;
}
}
/*
* out of deferrals
*/
if (name)
error(4, "%s: unknown name -- no native getconf(1) to defer to", name);
else
error(4, "no native getconf(1) to defer to");
return 2;
found:
/*
* don't blame us for crappy diagnostics
*/
oargv[0] = cmd;
if ((n = sh_run(context, argc, oargv)) >= EXIT_NOEXEC)
error(ERROR_SYSTEM|2, "%s: exec error [%d]", cmd, n);
return n;
}