Introduce 'function' built-in.

sh.c

@@ -112,34 +112,6 @@ static time_t chktim; /* Time mail last checked */
 char *progname;
 int tcsh;
 
-/*
- * This preserves the input state of the shell. It is used by
- * st_save and st_restore to manupulate shell state.
- */
-struct saved_state {
- int insource;
- int OLDSTD;
- int SHIN;
- int SHOUT;
- int SHDIAG;
- int intty;
- struct whyle *whyles;
- Char *gointr;
- Char *arginp;
- Char *evalp;
- Char **evalvec;
- Char *alvecp;
- Char **alvec;
- int onelflg;
- int enterhist;
- Char **argv;
- Char **av;
- Char HIST;
- int cantell;
- struct Bin B;
- int justpr;
-};
-
 static int srccat (Char *, Char *);
 #ifndef WINNT_NATIVE
 static int srcfile (const char *, int, int, Char **);
@@ -152,10 +124,6 @@ static void mailchk (void);
 static Char **defaultpath (void);
 #endif
 static void record (void);
-static void st_save (struct saved_state *, int, int,
- Char **, Char **);
-static void st_restore (void *);
-
  int main (int, char **);
 
 #ifndef LOCALEDIR
@@ -1569,7 +1537,7 @@ srcfile(const char *f, int onlyown, int flag, Char **av)
  * Save the shell state, and establish new argument vector, and new input
  * fd.
  */
-static void
+void
 st_save(struct saved_state *st, int unit, int hflg, Char **al, Char **av)
 {
  st->insource = insource;
@@ -1659,19 +1627,28 @@ st_save(struct saved_state *st, int unit, int hflg, Char **al, Char **av)
  gointr = 0;
  evalvec = 0;
  evalp = 0;
- alvec = al;
  alvecp = 0;
  enterhist = hflg;
  if (enterhist)
  HIST = '\0';
- insource = 1;
+ if (al == &fdecl) {
+ alvec = NULL;
+ insource = 2;
+ st->fpipe = fpipe;
+ st->fdecl = *al;
+ flvl++;
+ }
+ else {
+ alvec = al;
+ insource = 1;
+ }
 }
 
 
 /*
  * Restore the shell to a saved state
  */
-static void
+void
 st_restore(void *xst)
 {
  struct saved_state *st;
@@ -1696,6 +1673,12 @@ st_restore(void *xst)
 
  xclose(SHIN);
 
+ if (insource == 2) {
+ xclose(fpipe);
+ fpipe = st->fpipe;
+ fdecl = st->fdecl;
+ flvl--;
+ }
  insource = st->insource;
  SHIN = st->SHIN;
  if (st->OLDSTD != -1)

sh.decls.h

@@ -52,6 +52,8 @@ extern void done (int) __attribute__((__noreturn__));
 extern void xexit (int) __attribute__((__noreturn__));
 #endif
 extern int grabpgrp (int, pid_t);
+extern void st_save (struct saved_state *, int, int, Char **, Char **);
+extern void st_restore (void *);
 
 /*
  * sh.dir.c
@@ -150,6 +152,7 @@ extern void doend (Char **, struct command *);
 extern void doeval (Char **, struct command *);
 extern void doexit (Char **, struct command *);
 extern void doforeach (Char **, struct command *);
+extern void dofunction (Char **, struct command *);
 extern void doglob (Char **, struct command *);
 extern void dogoto (Char **, struct command *);
 extern void doif (Char **, struct command *);
@@ -164,6 +167,7 @@ extern void dohup (Char **, struct command *);
 extern void doonintr (Char **, struct command *);
 extern void doprintenv (Char **, struct command *);
 extern void dorepeat (Char **, struct command *);
+extern void doreturn (Char **, struct command *);
 extern void dofiletest (Char **, struct command *);
 extern void dosetenv (Char **, struct command *);
 extern void dosuspend (Char **, struct command *);

sh.err.c

@@ -188,7 +188,11 @@ extern int enterhist;
 #define ERR_BADCOLORVAR 134
 #define ERR_EOF 135
 #define ERR_UNAVAILABLE 136
-#define NO_ERRORS 137
+#define ERR_UNDFUNC 137
+#define ERR_FUNCBEGIN 138
+#define ERR_FUNCALNUM 139
+#define ERR_RECURSION 140
+#define NO_ERRORS 141
 
 static const char *elst[NO_ERRORS] INIT_ZERO_STRUCT;
 
@@ -367,7 +371,10 @@ errinit(void)
  elst[ERR_BADCOLORVAR] = CSAVS(1, 137, "Unknown %s color variable '%c%c'");
  elst[ERR_EOF] = CSAVS(1, 138, "Unexpected end of file");
  elst[ERR_UNAVAILABLE] = CSAVS(1, 139, "%s: Feature is not available for this platform");
-
+ elst[ERR_UNDFUNC] = CSAVS(1, 140, "%S: Undeclared function");
+ elst[ERR_FUNCBEGIN] = CSAVS(1, 142, "Function name must begin with a letter");
+ elst[ERR_FUNCALNUM] = CSAVS(1, 143, "Function name must contain alphanumeric characters");
+ elst[ERR_RECURSION] = CSAVS(1, 144, "Too deep a recursion or nest");
 }
 
 /* Cleanup data. */

sh.func.c

@@ -498,11 +498,18 @@ doexit(Char **v, struct command *c)
  stderror(ERR_NAME | ERR_EXPRESSION);
  }
  btoeof();
-#if 0
- if (intty)
-#endif
- /* Always close, why only on ttys? */
+
+ /* Always close, except in the context of
+ * dosource or dofunction.
+ * st_restore will handle. */
+ switch (insource) {
+ case 0:
  xclose(SHIN);
+ SHIN = -1;
+ break;
+ case 2:
+ fdecl += Strlen(fdecl);
+ }
 }
 
 /*ARGSUSED*/
@@ -1096,6 +1103,11 @@ getword(struct Strbuf *wp)
  stderror(ERR_NAME | ERR_NOTFOUND, "label");
  break;
 
+ case TC_EXIT:
+ setname(short2str(Sgoal));
+ stderror(ERR_NAME | ERR_NOTFOUND, "return");
+ break;
+
  default:
  break;
  }
@@ -2719,3 +2731,126 @@ getYN(const char *prompt)
  continue;
  return doit;
 }
+
+int flvl,
+ fpipe = -1;
+Char *fdecl;
+
+void
+dofunction(Char **v, struct command *c)
+{
+ if (*++v == NULL) {
+ plist(&functions, VAR_READONLY);
+
+ return;
+ }
+ Sgoal = *v++;
+ Stype = TC_EXIT;
+ {
+ int pv[2];
+ struct saved_state st;
+ struct varent *varp;
+ Char *p;
+
+ if (!letter(*(p = Sgoal)))
+ stderror(ERR_NAME | ERR_FUNCBEGIN);
+ while (*++p)
+ if (!alnum(*p))
+ stderror(ERR_NAME | ERR_FUNCALNUM);
+ if ((varp = adrof1(Sgoal, &functions))) {
+ if (flvl == 100)
+ stderror(ERR_RECURSION);
+ mypipe(pv);
+ cleanup_push(&st, st_restore);
+ st_save(&st, pv[0], 0, &fdecl, v);
+ fpipe = pv[1];
+ fdecl = *varp->vec;
+ process(0);
+ cleanup_until(&st);
+
+ return;
+ }
+ if (*v || c->t_dlef || c->t_drit ||
+ c->t_dflg & (F_PIPEIN | F_PIPEOUT))
+ stderror(ERR_UNDFUNC, Sgoal);
+ {
+ Char funcexit[] = { 'r', 'e', 't', 'u', 'r', 'n', '\0' },
+ alarg[] = { '!', '*', '\0' },
+ *(*varvec)[4];
+ struct Strbuf aword = Strbuf_INIT,
+ func = Strbuf_INIT;
+ struct wordent *histent = NULL,
+ *ohistent = NULL;
+
+ cleanup_push(&aword, Strbuf_cleanup);
+ while (1) {
+ if (intty) {
+ histent = xmalloc(sizeof(*histent));
+ ohistent = xmalloc(sizeof(*histent));
+ ohistent->word = STRNULL;
+ ohistent->next = histent;
+ histent->prev = ohistent;
+ }
+ if (intty && fseekp == feobp && aret == TCSH_F_SEEK)
+ printprompt(1, bname);
+ (void) getword(&aword);
+ Strbuf_terminate(&aword);
+ if (intty && Strlen(aword.s) > 0) {
+ histent->word = Strsave(aword.s);
+ histent->next = xmalloc(sizeof(*histent));
+ histent->next->prev = histent;
+ histent = histent->next;
+ }
+
+ if (eq(aword.s, funcexit))
+ break;
+ Strbuf_append(&func, aword.s);
+ Strbuf_append1(&func, ' ');
+ while (getword(&aword)) {
+ Strbuf_terminate(&aword);
+ if (intty && Strlen(aword.s) > 0) {
+ histent->word = Strsave(aword.s);
+ histent->next = xmalloc(sizeof(*histent));
+ histent->next->prev = histent;
+ histent = histent->next;
+ }
+ Strbuf_append(&func, aword.s);
+ Strbuf_append1(&func, ' ');
+ }
+ func.s[func.len - 1] = '\n';
+
+ if (intty) {
+ ohistent->prev = histgetword(histent);
+ ohistent->prev->next = ohistent;
+ savehist(ohistent, 0);
+ freelex(ohistent);
+ xfree(ohistent);
+ } else
+ (void) getword(NULL);
+ }
+
+ if (intty) {
+ ohistent->prev = histgetword(histent);
+ ohistent->prev->next = ohistent;
+ savehist(ohistent, 0);
+ freelex(ohistent);
+ xfree(ohistent);
+ }
+ cleanup_until(&aword);
+ if (!func.len)
+ return;
+ Strbuf_terminate(&func);
+ **(varvec = xcalloc(1, sizeof *varvec -
+ (sizeof **varvec * 2))) =
+ func.s;
+ setq(Sgoal, *varvec, &functions, VAR_READONLY);
+ **(varvec = xcalloc(1, sizeof *varvec)) =
+ Strsave(str2short(bname));
+ (*varvec)[1] = Strsave(Sgoal);
+ (*varvec)[2] = Strsave(alarg);
+ setq(Sgoal, *varvec, &aliases, VAR_READWRITE);
+
+ tw_cmd_free();
+ }
+ }
+}

sh.h

@@ -1019,7 +1019,9 @@ EXTERN struct varent {
 #define VAR_LAST 64
  struct varent *v_link[3]; /* The links, see below */
  int v_bal; /* Balance factor */
-} shvhed IZERO_STRUCT, aliases IZERO_STRUCT;
+} shvhed IZERO_STRUCT,
+ aliases IZERO_STRUCT,
+ functions IZERO_STRUCT;
 
 #define v_left v_link[0]
 #define v_right v_link[1]
@@ -1266,6 +1268,36 @@ EXTERN nl_catd catd;
 extern int filec;
 #endif /* FILEC */
 
+/*
+ * This preserves the input state of the shell. It is used by
+ * st_save and st_restore to manupulate shell state.
+ */
+struct saved_state {
+ int insource;
+ int OLDSTD;
+ int SHIN;
+ int SHOUT;
+ int SHDIAG;
+ int intty;
+ struct whyle *whyles;
+ Char *gointr;
+ Char *arginp;
+ Char *evalp;
+ Char **evalvec;
+ Char *alvecp;
+ Char **alvec;
+ int onelflg;
+ int enterhist;
+ Char **argv;
+ Char **av;
+ Char HIST;
+ int cantell;
+ struct Bin B;
+ int justpr;
+ int fpipe;
+ Char *fdecl;
+};
+
 #include "sh.decls.h"
 /*
  * Since on some machines characters are unsigned, and the signed
@@ -1305,5 +1337,10 @@ extern int filec;
 #define TEXP_IGNORE 1 /* in ignore, it means to ignore value, just parse */
 #define TEXP_NOGLOB 2 /* in ignore, it means not to globone */
 
+extern int flvl, /* Level of nesting or recursion used
+ * used by dofunction. */
+ fpipe; /* Write end of a pipe used by dofunction. */
+extern Char *fdecl; /* Pointer to function declaration
+ * used by dofunction. */
 
 #endif /* _h_sh */

sh.init.c

@@ -80,6 +80,7 @@ const struct biltins bfunc[] = {
  { "fg", dofg, 0, INF },
  { "filetest", dofiletest, 2, INF },
  { "foreach", doforeach, 3, INF },
+ { "function", dofunction, 0, INF },
 #ifdef TCF
  { "getspath", dogetspath, 0, 0 },
  { "getxvers", dogetxvers, 0, 0 },
@@ -122,6 +123,7 @@ const struct biltins bfunc[] = {
  { "pushd", dopushd, 0, INF },
  { "rehash", dohash, 0, 3 },
  { "repeat", dorepeat, 2, INF },
+ { "return", dozip, 0, 0 },
 #ifdef apollo
  { "rootnode", dorootnode, 1, 1 },
 #endif /* apollo */

sh.lex.c

@@ -1717,6 +1717,11 @@ bgetc(void)
  buf = (int) feobp / BUFSIZE;
  balloc(buf);
  roomleft = BUFSIZE - off;
+ if (insource == 2) {
+ if (!*fdecl)
+ return CHAR_ERR;
+ (void) xwrite(fpipe, fdecl++, (size_t) 1);
+ }
  c = wide_read(SHIN, fbuf[buf] + off, roomleft, 0);
  if (c > 0)
  feobp += c;