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author | jilles <jilles@FreeBSD.org> | 2013-02-03 15:54:57 +0000 |
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committer | jilles <jilles@FreeBSD.org> | 2013-02-03 15:54:57 +0000 |
commit | 6fa139d56eac8251b9a64c249c8e6fc8131f405c (patch) | |
tree | 798963ecfeaa133433ad99b27533d07fa1521c76 | |
parent | aa08976cf0559eb6c97a1886ea652e0f839759e5 (diff) | |
download | FreeBSD-src-6fa139d56eac8251b9a64c249c8e6fc8131f405c.zip FreeBSD-src-6fa139d56eac8251b9a64c249c8e6fc8131f405c.tar.gz |
sh: Expand here documents in the current process.
Expand here documents at the same point other redirections are expanded but
use a non-fork subshell environment (like simple command substitutions) for
compatibility. Substitition errors result in an empty here document like
before.
As a result, a fork is avoided for short (<4K) expanded here documents.
Unexpanded here documents (with quoted end marker after <<) are not affected
by this change. They already only forked when >4K.
Side effects:
* Order of expansion is slightly different.
* Slow expansions are not executed in parallel with the redirected command.
* A non-fork subshell environment is subtly different from a forked process.
-rw-r--r-- | bin/sh/eval.c | 35 | ||||
-rw-r--r-- | bin/sh/expand.c | 13 | ||||
-rw-r--r-- | bin/sh/expand.h | 1 | ||||
-rw-r--r-- | bin/sh/nodetypes | 1 | ||||
-rw-r--r-- | bin/sh/redir.c | 22 |
5 files changed, 48 insertions, 24 deletions
diff --git a/bin/sh/eval.c b/bin/sh/eval.c index 7817806..66ae40e 100644 --- a/bin/sh/eval.c +++ b/bin/sh/eval.c @@ -92,6 +92,7 @@ static void evalfor(union node *, int); static union node *evalcase(union node *); static void evalsubshell(union node *, int); static void evalredir(union node *, int); +static void exphere(union node *, struct arglist *); static void expredir(union node *); static void evalpipe(union node *); static int is_valid_fast_cmdsubst(union node *n); @@ -488,6 +489,37 @@ evalredir(union node *n, int flags) } +static void +exphere(union node *redir, struct arglist *fn) +{ + struct jmploc jmploc; + struct jmploc *savehandler; + struct localvar *savelocalvars; + int need_longjmp = 0; + + redir->nhere.expdoc = nullstr; + savelocalvars = localvars; + localvars = NULL; + forcelocal++; + savehandler = handler; + if (setjmp(jmploc.loc)) + need_longjmp = exception != EXERROR && exception != EXEXEC; + else { + handler = &jmploc; + expandarg(redir->nhere.doc, fn, 0); + redir->nhere.expdoc = fn->list->text; + INTOFF; + } + handler = savehandler; + forcelocal--; + poplocalvars(); + localvars = savelocalvars; + if (need_longjmp) + longjmp(handler->loc, 1); + INTON; +} + + /* * Compute the names of the files in a redirection list. */ @@ -516,6 +548,9 @@ expredir(union node *n) fixredir(redir, fn.list->text, 1); } break; + case NXHERE: + exphere(redir, &fn); + break; } } } diff --git a/bin/sh/expand.c b/bin/sh/expand.c index d43cc35..107f798 100644 --- a/bin/sh/expand.c +++ b/bin/sh/expand.c @@ -127,19 +127,6 @@ collate_range_cmp(wchar_t c1, wchar_t c2) return (wcscoll(s1, s2)); } -/* - * Expand shell variables and backquotes inside a here document. - * union node *arg the document - * int fd; where to write the expanded version - */ - -void -expandhere(union node *arg, int fd) -{ - expandarg(arg, (struct arglist *)NULL, 0); - xwrite(fd, stackblock(), expdest - stackblock()); -} - static char * stputs_quotes(const char *data, const char *syntax, char *p) { diff --git a/bin/sh/expand.h b/bin/sh/expand.h index 8114e2b..8d44321 100644 --- a/bin/sh/expand.h +++ b/bin/sh/expand.h @@ -57,7 +57,6 @@ struct arglist { union node; -void expandhere(union node *, int); void expandarg(union node *, struct arglist *, int); void expari(int); void rmescapes(char *); diff --git a/bin/sh/nodetypes b/bin/sh/nodetypes index ae4bc4a..5e70c64 100644 --- a/bin/sh/nodetypes +++ b/bin/sh/nodetypes @@ -138,6 +138,7 @@ NXHERE nhere # fd<<! next nodeptr # next redirection in list fd int # file descriptor being redirected doc nodeptr # input to command (NARG node) + expdoc temp char *expdoc # actual document (for NXHERE) NNOT nnot # ! command (actually pipeline) type int diff --git a/bin/sh/redir.c b/bin/sh/redir.c index 915b2fc..c11cb71 100644 --- a/bin/sh/redir.c +++ b/bin/sh/redir.c @@ -251,18 +251,23 @@ movefd: static int openhere(union node *redir) { + char *p; int pip[2]; int len = 0; if (pipe(pip) < 0) error("Pipe call failed: %s", strerror(errno)); - if (redir->type == NHERE) { - len = strlen(redir->nhere.doc->narg.text); - if (len <= PIPESIZE) { - xwrite(pip[1], redir->nhere.doc->narg.text, len); - goto out; - } + + if (redir->type == NXHERE) + p = redir->nhere.expdoc; + else + p = redir->nhere.doc->narg.text; + len = strlen(p); + if (len <= PIPESIZE) { + xwrite(pip[1], p, len); + goto out; } + if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { close(pip[0]); signal(SIGINT, SIG_IGN); @@ -270,10 +275,7 @@ openhere(union node *redir) signal(SIGHUP, SIG_IGN); signal(SIGTSTP, SIG_IGN); signal(SIGPIPE, SIG_DFL); - if (redir->type == NHERE) - xwrite(pip[1], redir->nhere.doc->narg.text, len); - else - expandhere(redir->nhere.doc, pip[1]); + xwrite(pip[1], p, len); _exit(0); } out: |