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Diffstat (limited to 'src/var.c')
| -rw-r--r-- | src/var.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/src/var.c b/src/var.c new file mode 100644 index 0000000..0908840 --- /dev/null +++ b/src/var.c @@ -0,0 +1,689 @@ +/* $NetBSD: var.c,v 1.32 2003/01/22 20:36:04 dsl Exp $ */ + +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +#ifndef lint +#if 0 +static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; +#else +__RCSID("$NetBSD: var.c,v 1.32 2003/01/22 20:36:04 dsl Exp $"); +#endif +#endif /* not lint */ + +#include <unistd.h> +#include <stdlib.h> +#include <paths.h> + +/* + * Shell variables. + */ + +#include "shell.h" +#include "output.h" +#include "expand.h" +#include "nodes.h" /* for other headers */ +#include "eval.h" /* defines cmdenviron */ +#include "exec.h" +#include "syntax.h" +#include "options.h" +#include "mail.h" +#include "var.h" +#include "memalloc.h" +#include "error.h" +#include "mystring.h" +#include "parser.h" +#include "show.h" +#ifndef SMALL +#include "myhistedit.h" +#endif +#include "system.h" + + +#define VTABSIZE 39 + + +struct localvar *localvars; + +const char defpathvar[] = + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"; +#ifdef IFS_BROKEN +const char defifsvar[] = "IFS= \t\n"; +#else +const char defifs[] = " \t\n"; +#endif + +struct var varinit[] = { +#if ATTY + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY\0", 0 }, +#endif +#ifdef IFS_BROKEN + { 0, VSTRFIXED|VTEXTFIXED, defifsvar, 0 }, +#else + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "IFS\0", 0 }, +#endif + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL\0", changemail }, + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH\0", changemail }, + { 0, VSTRFIXED|VTEXTFIXED, defpathvar, changepath }, + { 0, VSTRFIXED|VTEXTFIXED, "PS1=$ ", 0 }, + { 0, VSTRFIXED|VTEXTFIXED, "PS2=> ", 0 }, + { 0, VSTRFIXED|VTEXTFIXED, "PS4=+ ", 0 }, + { 0, VSTRFIXED|VTEXTFIXED, "OPTIND=1", getoptsreset }, +#ifndef SMALL + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM\0", 0 }, + { 0, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE\0", sethistsize }, +#endif +}; + +STATIC struct var *vartab[VTABSIZE]; + +STATIC void mklocal(char *); +STATIC struct var **hashvar(const char *); +STATIC int vpcmp(const void *, const void *); +STATIC struct var **findvar(struct var **, const char *); + +/* + * Initialize the varable symbol tables and import the environment + */ + +#ifdef mkinit +INCLUDE <unistd.h> +INCLUDE <sys/types.h> +INCLUDE <sys/stat.h> +INCLUDE "cd.h" +INCLUDE "output.h" +INCLUDE "var.h" +MKINIT char **environ; +INIT { + char **envp; + static char ppid[32] = "PPID="; + const char *p; + struct stat st1, st2; + + initvar(); + for (envp = environ ; *envp ; envp++) { + if (strchr(*envp, '=')) { + setvareq(*envp, VEXPORT|VTEXTFIXED); + } + } + + fmtstr(ppid + 5, sizeof(ppid) - 5, "%ld", (long) getppid()); + setvareq(ppid, VTEXTFIXED); + + p = lookupvar("PWD"); + if (p) + if (*p != '/' || stat(p, &st1) || stat(".", &st2) || + st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) + p = 0; + setpwd(p, 0); +} +#endif + + +/* + * This routine initializes the builtin variables. It is called when the + * shell is initialized. + */ + +void +initvar(void) +{ + struct var *vp; + struct var *end; + struct var **vpp; + + vp = varinit; + end = vp + sizeof(varinit) / sizeof(varinit[0]); + do { + vpp = hashvar(vp->text); + vp->next = *vpp; + *vpp = vp; + } while (++vp < end); + /* + * PS1 depends on uid + */ + if (!geteuid()) + vps1.text = "PS1=# "; +} + +/* + * Safe version of setvar, returns 1 on success 0 on failure. + */ + +int +setvarsafe(const char *name, const char *val, int flags) +{ + int err; + volatile int saveint; + struct jmploc *volatile savehandler = handler; + struct jmploc jmploc; + + SAVEINT(saveint); + if (setjmp(jmploc.loc)) + err = 1; + else { + handler = &jmploc; + setvar(name, val, flags); + err = 0; + } + handler = savehandler; + RESTOREINT(saveint); + return err; +} + +/* + * 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. + */ + +void +setvar(const char *name, const char *val, int flags) +{ + char *p, *q; + size_t namelen; + char *nameeq; + size_t vallen; + + q = endofname(name); + p = strchrnul(q, '='); + namelen = p - name; + if (!namelen || p != q) + error("%.*s: bad variable name", namelen, name); + vallen = 0; + if (val == NULL) { + flags |= VUNSET; + } else { + vallen = strlen(val); + } + INTOFF; + p = mempcpy(nameeq = ckmalloc(namelen + vallen + 2), name, namelen); + *p++ = '\0'; + if (vallen) { + p[-1] = '='; + p = mempcpy(p, val, vallen); + } + *p = '\0'; + setvareq(nameeq, flags | VNOSAVE); + INTON; +} + + + +/* + * 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. + * Called with interrupts off. + */ + +void +setvareq(char *s, int flags) +{ + struct var *vp, **vpp; + + vpp = hashvar(s); + flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1)); + vp = *findvar(vpp, s); + if (vp) { + if (vp->flags & VREADONLY) { + const char *n; + + if (flags & VNOSAVE) + free(s); + n = vp->text; + error("%.*s: is read only", strchrnul(n, '=') - n, n); + } + + if (flags & VNOSET) + return; + + if (vp->func && (flags & VNOFUNC) == 0) + (*vp->func)(strchrnul(s, '=') + 1); + + if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) + ckfree(vp->text); + + flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET); + } else { + if (flags & VNOSET) + return; + /* not found */ + vp = ckmalloc(sizeof (*vp)); + vp->next = *vpp; + vp->func = NULL; + *vpp = vp; + } + if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE))) + s = savestr(s); + vp->text = s; + vp->flags = flags; +} + + + +/* + * Process a linked list of variable assignments. + */ + +void +listsetvar(struct strlist *list, int flags) +{ + struct strlist *lp; + + lp = list; + if (!lp) + return; + INTOFF; + do { + setvareq(lp->text, flags); + } while ((lp = lp->next)); + INTON; +} + + +/* + * Find the value of a variable. Returns NULL if not set. + */ + +char * +lookupvar(const char *name) +{ + struct var *v; + + if ((v = *findvar(hashvar(name), name)) && !(v->flags & VUNSET)) { + return strchrnul(v->text, '=') + 1; + } + return NULL; +} + + + +/* + * Search the environment of a builtin command. + */ + +char * +bltinlookup(const char *name) +{ + struct strlist *sp; + + for (sp = cmdenviron ; sp ; sp = sp->next) { + if (varequal(sp->text, name)) + return strchrnul(sp->text, '=') + 1; + } + return lookupvar(name); +} + + + +/* + * Generate a list of variables satisfying the given conditions. + */ + +char ** +listvars(int on, int off, char ***end) +{ + struct var **vpp; + struct var *vp; + char **ep; + int mask; + + STARTSTACKSTR(ep); + vpp = vartab; + mask = on | off; + do { + for (vp = *vpp ; vp ; vp = vp->next) + if ((vp->flags & mask) == on) { + if (ep == stackstrend()) + ep = growstackstr(); + *ep++ = (char *) vp->text; + } + } while (++vpp < vartab + VTABSIZE); + if (ep == stackstrend()) + ep = growstackstr(); + if (end) + *end = ep; + *ep++ = NULL; + return grabstackstr(ep); +} + + + +/* + * POSIX requires that 'set' (but not export or readonly) output the + * variables in lexicographic order - by the locale's collating order (sigh). + * Maybe we could keep them in an ordered balanced binary tree + * instead of hashed lists. + * For now just roll 'em through qsort for printing... + */ + +int +showvars(const char *prefix, int on, int off) +{ + const char *sep; + char **ep, **epend; + + ep = listvars(on, off, &epend); + qsort(ep, epend - ep, sizeof(char *), vpcmp); + + sep = *prefix ? spcstr : prefix; + + for (; ep < epend; ep++) { + const char *p; + const char *q; + + p = strchrnul(*ep, '='); + q = nullstr; + if (*p) + q = single_quote(++p); + + out1fmt("%s%s%.*s%s\n", prefix, sep, (int)(p - *ep), *ep, q); + } + + return 0; +} + + + +/* + * The export and readonly commands. + */ + +int +exportcmd(int argc, char **argv) +{ + struct var *vp; + char *name; + const char *p; + char **aptr; + int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; + int notp; + + notp = nextopt("p") - 'p'; + if (notp && ((name = *(aptr = argptr)))) { + do { + if ((p = strchr(name, '=')) != NULL) { + p++; + } else { + if ((vp = *findvar(hashvar(name), name))) { + vp->flags |= flag; + continue; + } + } + setvar(name, p, flag); + } while ((name = *++aptr) != NULL); + } else { + showvars(argv[0], flag, 0); + } + return 0; +} + + +/* + * The "local" command. + */ + +int +localcmd(int argc, char **argv) +{ + char *name; + + argv = argptr; + while ((name = *argv++) != NULL) { + mklocal(name); + } + return 0; +} + + +/* + * Make a variable a local variable. When a variable is made local, it's + * value and flags are saved in a localvar structure. The saved values + * will be restored when the shell function returns. We handle the name + * "-" as a special case. + */ + +STATIC void +mklocal(char *name) +{ + struct localvar *lvp; + struct var **vpp; + struct var *vp; + + INTOFF; + lvp = ckmalloc(sizeof (struct localvar)); + if (name[0] == '-' && name[1] == '\0') { + char *p; + p = ckmalloc(sizeof(optlist)); + lvp->text = memcpy(p, optlist, sizeof(optlist)); + vp = NULL; + } else { + char *eq; + + vpp = hashvar(name); + vp = *findvar(vpp, name); + eq = strchr(name, '='); + if (vp == NULL) { + if (eq) + setvareq(name, VSTRFIXED); + else + setvar(name, NULL, VSTRFIXED); + vp = *vpp; /* the new variable */ + lvp->flags = VUNSET; + } else { + lvp->text = vp->text; + lvp->flags = vp->flags; + vp->flags |= VSTRFIXED|VTEXTFIXED; + if (eq) + setvareq(name, 0); + } + } + lvp->vp = vp; + lvp->next = localvars; + localvars = lvp; + INTON; +} + + +/* + * Called after a function returns. + * Interrupts must be off. + */ + +void +poplocalvars(void) +{ + struct localvar *lvp; + struct var *vp; + + while ((lvp = localvars) != NULL) { + localvars = lvp->next; + vp = lvp->vp; + TRACE(("poplocalvar %s", vp ? vp->text : "-")); + if (vp == NULL) { /* $- saved */ + memcpy(optlist, lvp->text, sizeof(optlist)); + ckfree(lvp->text); + optschanged(); + } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { + unsetvar(vp->text); + } else { + if (vp->func) + (*vp->func)(strchrnul(lvp->text, '=') + 1); + if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) + ckfree(vp->text); + vp->flags = lvp->flags; + vp->text = lvp->text; + } + ckfree(lvp); + } +} + + +/* + * The unset builtin command. We unset the function before we unset the + * variable to allow a function to be unset when there is a readonly variable + * with the same name. + */ + +int +unsetcmd(int argc, char **argv) +{ + char **ap; + int i; + int flag = 0; + int ret = 0; + + while ((i = nextopt("vf")) != '\0') { + flag = i; + } + + for (ap = argptr; *ap ; ap++) { + if (flag != 'f') { + i = unsetvar(*ap); + ret |= i; + if (!(i & 2)) + continue; + } + if (flag != 'v') + unsetfunc(*ap); + } + return ret & 1; +} + + +/* + * Unset the specified variable. + */ + +int +unsetvar(const char *s) +{ + struct var **vpp; + struct var *vp; + int retval; + + vpp = findvar(hashvar(s), s); + vp = *vpp; + retval = 2; + if (vp) { + int flags = vp->flags; + + retval = 1; + if (flags & VREADONLY) + goto out; + if (flags & VUNSET) + goto ok; + if ((flags & VSTRFIXED) == 0) { + INTOFF; + if ((flags & (VTEXTFIXED|VSTACK)) == 0) + ckfree(vp->text); + *vpp = vp->next; + ckfree(vp); + INTON; + } else { + setvar(s, 0, 0); + vp->flags &= ~VEXPORT; + } +ok: + retval = 0; + } + +out: + return retval; +} + + + +/* + * Find the appropriate entry in the hash table from the name. + */ + +STATIC struct var ** +hashvar(const char *p) +{ + unsigned int hashval; + + hashval = ((unsigned char) *p) << 4; + while (*p && *p != '=') + hashval += (unsigned char) *p++; + return &vartab[hashval % VTABSIZE]; +} + + + +/* + * Compares two strings up to the first = or '\0'. The first + * string must be terminated by '='; the second may be terminated by + * either '=' or '\0'. + */ + +int +varcmp(const char *p, const char *q) +{ + int c, d; + + while ((c = *p) == (d = *q)) { + if (!c || c == '=') + goto out; + p++; + q++; + } + if (c == '=') + c = 0; + if (d == '=') + d = 0; +out: + return c - d; +} + +STATIC int +vpcmp(const void *a, const void *b) +{ + return varcmp(*(const char **)a, *(const char **)b); +} + +STATIC struct var ** +findvar(struct var **vpp, const char *name) +{ + for (; *vpp; vpp = &(*vpp)->next) { + if (varequal((*vpp)->text, name)) { + break; + } + } + return vpp; +} |