Module Name: src
Committed By: kre
Date: Fri Jun 30 23:05:45 UTC 2017
Modified Files:
src/bin/sh: Makefile var.c var.h
Log Message:
Implement a bunch of new shell environment variables. many mostly useful
in prompts when expanded at prompt time, but all available for general use.
Many of the new ones are not available in SMALL shells (they work as normal
if assigned, but the shell does not set or use them - and there is no magic
in a SMALL shell (usually for install media.))
To generate a diff of this commit:
cvs rdiff -u -r1.112 -r1.113 src/bin/sh/Makefile
cvs rdiff -u -r1.62 -r1.63 src/bin/sh/var.c
cvs rdiff -u -r1.34 -r1.35 src/bin/sh/var.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/bin/sh/Makefile
diff -u src/bin/sh/Makefile:1.112 src/bin/sh/Makefile:1.113
--- src/bin/sh/Makefile:1.112 Thu Jun 8 02:25:43 2017
+++ src/bin/sh/Makefile Fri Jun 30 23:05:45 2017
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.112 2017/06/08 02:25:43 kre Exp $
+# $NetBSD: Makefile,v 1.113 2017/06/30 23:05:45 kre Exp $
# @(#)Makefile 8.4 (Berkeley) 5/5/95
.include <bsd.own.mk>
@@ -24,6 +24,7 @@ SCRIPT_ENV= \
SED=${TOOL_SED:Q}
CPPFLAGS+=-DSHELL -I. -I${.CURDIR}
+CPPFLAGS+= -DUSE_LRAND48
#XXX: For testing only.
#CPPFLAGS+=-DDEBUG=3
#COPTS+=-g
@@ -90,6 +91,7 @@ SUBDIR+=USD.doc
COPTS.printf.c = -Wno-format-nonliteral
COPTS.jobs.c = -Wno-format-nonliteral
+COPTS.var.c = -Wno-format-nonliteral
.include <bsd.prog.mk>
.include <bsd.subdir.mk>
Index: src/bin/sh/var.c
diff -u src/bin/sh/var.c:1.62 src/bin/sh/var.c:1.63
--- src/bin/sh/var.c:1.62 Wed Jun 28 13:46:06 2017
+++ src/bin/sh/var.c Fri Jun 30 23:05:45 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: var.c,v 1.62 2017/06/28 13:46:06 kre Exp $ */
+/* $NetBSD: var.c,v 1.63 2017/06/30 23:05:45 kre Exp $ */
/*-
* Copyright (c) 1991, 1993
@@ -37,7 +37,7 @@
#if 0
static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
#else
-__RCSID("$NetBSD: var.c,v 1.62 2017/06/28 13:46:06 kre Exp $");
+__RCSID("$NetBSD: var.c,v 1.63 2017/06/30 23:05:45 kre Exp $");
#endif
#endif /* not lint */
@@ -47,6 +47,9 @@ __RCSID("$NetBSD: var.c,v 1.62 2017/06/2
#include <string.h>
#include <paths.h>
#include <limits.h>
+#include <time.h>
+#include <pwd.h>
+#include <fcntl.h>
/*
* Shell variables.
@@ -68,6 +71,7 @@ __RCSID("$NetBSD: var.c,v 1.62 2017/06/2
#include "mystring.h"
#include "parser.h"
#include "show.h"
+#include "machdep.h"
#ifndef SMALL
#include "myhistedit.h"
#endif
@@ -90,6 +94,14 @@ struct varinit {
char *get_lineno(struct var *);
+#ifndef SMALL
+char *get_tod(struct var *);
+char *get_hostname(struct var *);
+char *get_seconds(struct var *);
+char *get_euser(struct var *);
+char *get_random(struct var *);
+#endif
+
struct localvar *localvars;
#ifndef SMALL
@@ -108,6 +120,15 @@ struct var vps4;
struct var vvers;
struct var voptind;
struct var line_num;
+#ifndef SMALL
+struct var tod;
+struct var host_name;
+struct var seconds;
+struct var euname;
+struct var random_num;
+
+intmax_t sh_start_time;
+#endif
struct var line_num;
int line_number;
@@ -150,6 +171,18 @@ const struct varinit varinit[] = {
{ .set_func= getoptsreset } },
{ &line_num, VSTRFIXED|VTEXTFIXED|VFUNCREF, "LINENO=1",
{ .ref_func= get_lineno } },
+#ifndef SMALL
+ { &tod, VSTRFIXED|VTEXTFIXED|VFUNCREF, "ToD=",
+ { .ref_func= get_tod } },
+ { &host_name, VSTRFIXED|VTEXTFIXED|VFUNCREF, "HOSTNAME=",
+ { .ref_func= get_hostname } },
+ { &seconds, VSTRFIXED|VTEXTFIXED|VFUNCREF, "SECONDS=",
+ { .ref_func= get_seconds } },
+ { &euname, VSTRFIXED|VTEXTFIXED|VFUNCREF, "EUSER=",
+ { .ref_func= get_euser } },
+ { &random_num, VSTRFIXED|VTEXTFIXED|VFUNCREF, "RANDOM=",
+ { .ref_func= get_random } },
+#endif
{ NULL, 0, NULL,
{ NULL } }
};
@@ -166,6 +199,7 @@ STATIC struct var *find_var(const char *
#ifdef mkinit
INCLUDE <stdio.h>
INCLUDE <unistd.h>
+INCLUDE <time.h>
INCLUDE "var.h"
INCLUDE "version.h"
MKINIT char **environ;
@@ -173,7 +207,18 @@ INIT {
char **envp;
char buf[64];
+#ifndef SMALL
+ sh_start_time = (intmax_t)time((time_t *)0);
+#endif
+ /*
+ * Set up our default variables and their values.
+ */
initvar();
+
+ /*
+ * Import variables from the environment, which will
+ * override anything initialised just previously.
+ */
for (envp = environ ; *envp ; envp++) {
if (strchr(*envp, '=')) {
setvareq(*envp, VEXPORT|VTEXTFIXED);
@@ -185,12 +230,20 @@ INIT {
*
* PPID is readonly
* Always default IFS
+ * PSc indicates the root/non-root status of this shell.
* NETBSD_SHELL is a constant (readonly), and is never exported
+ * START_TIME belongs only to this shell.
* LINENO is simply magic...
*/
snprintf(buf, sizeof(buf), "%d", (int)getppid());
setvar("PPID", buf, VREADONLY);
setvar("IFS", ifs_default, VTEXTFIXED);
+ setvar("PSc", (geteuid() == 0 ? "#" : "$"), VTEXTFIXED);
+
+#ifndef SMALL
+ snprintf(buf, sizeof(buf), "%jd", sh_start_time);
+ setvar("START_TIME", buf, VTEXTFIXED);
+#endif
setvar("NETBSD_SHELL", NETBSD_SHELL
#ifdef BUILD_DATE
@@ -248,7 +301,7 @@ initvar(void)
vp->next = *vpp;
*vpp = vp;
vp->text = strdup(ip->text);
- vp->flags = ip->flags;
+ vp->flags = (ip->flags & ~VTEXTFIXED) | VSTRFIXED;
vp->v_u = ip->v_u;
}
/*
@@ -257,7 +310,7 @@ initvar(void)
if (find_var("PS1", &vpp, &vps1.name_len) == NULL) {
vps1.next = *vpp;
*vpp = &vps1;
- vps1.flags = VSTRFIXED|VTEXTFIXED;
+ vps1.flags = VSTRFIXED;
vps1.text = NULL;
choose_ps1();
}
@@ -266,8 +319,15 @@ initvar(void)
void
choose_ps1(void)
{
- free(vps1.text);
+ if ((vps1.flags & (VTEXTFIXED|VSTACK)) == 0)
+ free(vps1.text);
vps1.text = strdup(geteuid() ? "PS1=$ " : "PS1=# ");
+ vps1.flags &= ~(VTEXTFIXED|VSTACK);
+
+ /*
+ * Update PSc whenever we feel the need to update PS1
+ */
+ setvarsafe("PSc", (geteuid() == 0 ? "#" : "$"), 0);
}
/*
@@ -294,6 +354,11 @@ setvarsafe(const char *name, const char
/*
* Set the value of a variable. The flags argument is ored with the
* flags of the variable. If val is NULL, the variable is unset.
+ *
+ * This always copies name and val when setting a variable, so
+ * the source strings can be from anywhere, and are no longer needed
+ * after this function returns. The VTEXTFIXED and VSTACK flags should
+ * not be used (but just in case they were, clear them.)
*/
void
@@ -337,7 +402,7 @@ setvar(const char *name, const char *val
*d = '\0';
if (val)
scopy(val, d);
- setvareq(nameeq, flags);
+ setvareq(nameeq, flags & ~(VTEXTFIXED | VSTACK));
}
@@ -346,7 +411,9 @@ setvar(const char *name, const char *val
* Same as setvar except that the variable and value are passed in
* the first argument as name=value. Since the first argument will
* be actually stored in the table, it should not be a string that
- * will go away.
+ * will go away. The flags (VTEXTFIXED or VSTACK) can be used to
+ * indicate the source of the string (if neither is set, the string will
+ * eventually be free()d when a replacement value is assigned.)
*/
void
@@ -405,7 +472,7 @@ setvareq(char *s, int flags)
return;
}
vp = ckmalloc(sizeof (*vp));
- vp->flags = flags & ~(VNOFUNC|VFUNCREF);
+ vp->flags = flags & ~(VNOFUNC|VFUNCREF|VSTRFIXED);
vp->text = s;
vp->name_len = nlen;
vp->next = *vpp;
@@ -1058,16 +1125,304 @@ find_var(const char *name, struct var **
return NULL;
}
+/*
+ * The following are the functions that create the values for
+ * shell variables that are dynamically produced when needed.
+ *
+ * The output strings cannot be malloc'd as there is nothing to
+ * free them - callers assume these are ordinary variables where
+ * the value returned is vp->text
+ *
+ * Each function needs its own storage space, as the results are
+ * used to create processes' environment, and (if exported) all
+ * the values will (might) be needed simultaneously.
+ *
+ * It is not a problem if a var is updated while nominally in use
+ * somewhere, all these are intended to be dynamic, the value they
+ * return is not guaranteed, an updated vaue is just as good.
+ *
+ * So, malloc a single buffer for the result of each function,
+ * grow, and even shrink, it as needed, but once we have one that
+ * is a suitable size for the actual usage, simply hold it forever.
+ *
+ * For a SMALL shell we implement only LINENO, none of the others,
+ * and give it just a fixed length static buffer for its result.
+ */
+
+#ifndef SMALL
+
+struct space_reserved { /* record of space allocated for results */
+ char *b;
+ int len;
+};
+
+/* rough (over-)estimate of the number of bytes needed to hold a number */
+static int
+digits_in(intmax_t number)
+{
+ int res = 0;
+
+ if (number & ~((1LL << 62) - 1))
+ res = 64; /* enough for 2^200 and a bit more */
+ else if (number & ~((1LL << 32) - 1))
+ res = 20; /* enough for 2^64 */
+ else if (number & ~((1 << 23) - 1))
+ res = 10; /* enough for 2^32 */
+ else
+ res = 8; /* enough for 2^23 or smaller */
+
+ return res;
+}
+
+static int
+make_space(struct space_reserved *m, int bytes)
+{
+ void *p;
+
+ if (m->len >= bytes && m->len <= (bytes<<2))
+ return 1;
+
+ bytes = SHELL_ALIGN(bytes);
+ /* not ckrealloc() - we want failure, not error() here */
+ p = realloc(m->b, bytes);
+ if (p == NULL) /* what we had should still be there */
+ return 0;
+
+ m->b = p;
+ m->len = bytes;
+ m->b[bytes - 1] = '\0';
+
+ return 1;
+}
+#endif
+
char *
get_lineno(struct var *vp)
{
- static char lineno_buf[8 + 14];
+#ifdef SMALL
+#define length (8 + 10) /* 10 digits is enough for a 32 bit line num */
+ static char result[length];
+#else
+ static struct space_reserved buf;
+#define result buf.b
+#define length buf.len
+#endif
int ln = line_number;
if (vp->flags & VUNSET)
return NULL;
ln -= funclinebase;
- snprintf(lineno_buf, sizeof(lineno_buf), "LINENO=%d", ln);;
- return lineno_buf;
+
+#ifndef SMALL
+ if (!make_space(&buf, vp->name_len + 2 + digits_in(ln)))
+ return vp->text;
+#endif
+
+ snprintf(result, length - 1, "%.*s=%d", vp->name_len, vp->text, ln);
+ return result;
+}
+#undef result
+#undef length
+
+#ifndef SMALL
+
+char *
+get_hostname(struct var *vp)
+{
+ static struct space_reserved buf;
+
+ if (vp->flags & VUNSET)
+ return NULL;
+
+ if (!make_space(&buf, vp->name_len + 2 + 256))
+ return vp->text;
+
+ memcpy(buf.b, vp->text, vp->name_len + 1); /* include '=' */
+ (void)gethostname(buf.b + vp->name_len + 1,
+ buf.len - vp->name_len - 3);
+ return buf.b;
+}
+
+char *
+get_tod(struct var *vp)
+{
+ static struct space_reserved buf; /* space for answers */
+ static struct space_reserved tzs; /* remember TZ last used */
+ static timezone_t last_zone; /* timezone data for tzs zone */
+ const char *fmt;
+ char *tz;
+ time_t now;
+ struct tm tm_now, *tmp;
+ timezone_t zone = NULL;
+ static char t_err[] = "time error";
+ int len;
+
+ if (vp->flags & VUNSET)
+ return NULL;
+
+ fmt = lookupvar("ToD_FORMAT");
+ if (fmt == NULL)
+ fmt="%T";
+ tz = lookupvar("TZ");
+ (void)time(&now);
+
+ if (tz != NULL) {
+ if (tzs.b == NULL || strcmp(tzs.b, tz) != 0) {
+ if (make_space(&tzs, strlen(tz) + 1)) {
+ INTOFF;
+ strcpy(tzs.b, tz);
+ if (last_zone)
+ tzfree(last_zone);
+ last_zone = zone = tzalloc(tz);
+ INTON;
+ } else
+ zone = tzalloc(tz);
+ } else
+ zone = last_zone;
+
+ tmp = localtime_rz(zone, &now, &tm_now);
+ } else
+ tmp = localtime_r(&now, &tm_now);
+
+ len = (strlen(fmt) * 4) + vp->name_len + 2;
+ while (make_space(&buf, len)) {
+ memcpy(buf.b, vp->text, vp->name_len+1);
+ if (tmp == NULL) {
+ if (buf.len >= vp->name_len+2+(int)(sizeof t_err - 1)) {
+ strcpy(buf.b + vp->name_len + 1, t_err);
+ if (zone && zone != last_zone)
+ tzfree(zone);
+ return buf.b;
+ }
+ len = vp->name_len + 4 + sizeof t_err - 1;
+ continue;
+ }
+ if (strftime_z(zone, buf.b + vp->name_len + 1,
+ buf.len - vp->name_len - 2, fmt, tmp)) {
+ if (zone && zone != last_zone)
+ tzfree(zone);
+ return buf.b;
+ }
+ if (len >= 4096) /* Let's be reasonable */
+ break;
+ len <<= 1;
+ }
+ if (zone && zone != last_zone)
+ tzfree(zone);
+ return vp->text;
}
+
+char *
+get_seconds(struct var *vp)
+{
+ static struct space_reserved buf;
+ intmax_t secs;
+
+ if (vp->flags & VUNSET)
+ return NULL;
+
+ secs = (intmax_t)time((time_t *)0) - sh_start_time;
+ if (!make_space(&buf, vp->name_len + 2 + digits_in(secs)))
+ return vp->text;
+
+ snprintf(buf.b, buf.len-1, "%.*s=%jd", vp->name_len, vp->text, secs);
+ return buf.b;
+}
+
+char *
+get_euser(struct var *vp)
+{
+ static struct space_reserved buf;
+ static uid_t lastuid = 0;
+ uid_t euid;
+ struct passwd *pw;
+
+ if (vp->flags & VUNSET)
+ return NULL;
+
+ euid = geteuid();
+ if (buf.b != NULL && lastuid == euid)
+ return buf.b;
+
+ pw = getpwuid(euid);
+ if (pw == NULL)
+ return vp->text;
+
+ if (make_space(&buf, vp->name_len + 2 + strlen(pw->pw_name))) {
+ lastuid = euid;
+ snprintf(buf.b, buf.len, "%.*s=%s", vp->name_len, vp->text,
+ pw->pw_name);
+ return buf.b;
+ }
+
+ return vp->text;
+}
+
+char *
+get_random(struct var *vp)
+{
+ static struct space_reserved buf;
+ static intmax_t random_val = 0;
+
+#ifdef USE_LRAND48
+#define random lrand48
+#define srandom srand48
+#endif
+
+ if (vp->flags & VUNSET)
+ return NULL;
+
+ if (vp->text != buf.b) {
+ /*
+ * Either initialisation, or a new seed has been set
+ */
+ if (vp->text[vp->name_len + 1] == '\0') {
+ int fd;
+
+ /*
+ * initialisation (without pre-seeding),
+ * or explictly requesting a truly random seed.
+ */
+ fd = open("/dev/urandom", 0);
+ if (fd == -1) {
+ out2str("RANDOM initialisation failed\n");
+ random_val = (getpid()<<3) ^ time((time_t *)0);
+ } else {
+ int n;
+
+ do {
+ n = read(fd,&random_val,sizeof random_val);
+ } while (n != sizeof random_val);
+ close(fd);
+ }
+ } else
+ /* good enough for today */
+ random_val = atoi(vp->text + vp->name_len + 1);
+
+ srandom((long)random_val);
+ }
+
+#if 0
+ random_val = (random_val + 1) & 0x7FFF; /* 15 bit "random" numbers */
+#else
+ random_val = (random() >> 5) & 0x7FFF;
+#endif
+
+ if (!make_space(&buf, vp->name_len + 2 + digits_in(random_val)))
+ return vp->text;
+
+ snprintf(buf.b, buf.len-1, "%.*s=%jd", vp->name_len, vp->text,
+ random_val);
+
+ if (buf.b != vp->text && (vp->flags & (VTEXTFIXED|VSTACK)) == 0)
+ free(vp->text);
+ vp->flags |= VTEXTFIXED;
+ vp->text = buf.b;
+
+ return vp->text;
+#undef random
+#undef srandom
+}
+
+#endif /* SMALL */
Index: src/bin/sh/var.h
diff -u src/bin/sh/var.h:1.34 src/bin/sh/var.h:1.35
--- src/bin/sh/var.h:1.34 Wed Jun 28 13:46:06 2017
+++ src/bin/sh/var.h Fri Jun 30 23:05:45 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: var.h,v 1.34 2017/06/28 13:46:06 kre Exp $ */
+/* $NetBSD: var.h,v 1.35 2017/06/30 23:05:45 kre Exp $ */
/*-
* Copyright (c) 1991, 1993
@@ -95,6 +95,9 @@ extern struct var vterm;
extern struct var vtermcap;
extern struct var vhistsize;
extern struct var ps_lit;
+extern struct var euname;
+extern struct var random_num;
+extern intmax_t sh_start_time;
#endif
extern int line_number;
