.\" Case Western Reserve University
.\" chet.ramey@case.edu
.\"
-.\" Last Change: Tue Feb 26 09:46:20 EST 2019
+.\" Last Change: Sun Mar 24 14:05:55 EDT 2019
.\"
.\" bash_builtins, strip all but Built-Ins section
.if \n(zZ=1 .ig zZ
.if \n(zY=1 .ig zY
-.TH BASH 1 "2019 February 26" "GNU Bash 5.0"
+.TH BASH 1 "2019 March 24" "GNU Bash 5.0"
.\"
.\" There's some problem with having a `@'
.\" in a tagged paragraph with the BSD man macros.
.PP
When the shell is waiting for a job or process using the \fBwait\fP
builtin, and job control is enabled, \fBwait\fP will return when the
-job changes state. The \fB\-f\fP option will force \fBwait\fP to wait
+job changes state. The \fB\-f\fP option causes \fBwait\fP to wait
until the job or process terminates before returning.
.SH PROMPTING
When executing interactively,
are waited for, and the return status is zero.
If the \fB\-n\fP option is supplied, \fBwait\fP waits for any job to
terminate and returns its exit status.
-If the \fB\-f\fP option is supplied, and job control is enabled,
-\fBwait\fP forces \fIid\fP to terminate before returning its status,
-instead of returning when it changes status.
+Supplying the \fB\-f\fP option, when job control is enabled,
+forces \fBwait\fP to wait for \fIid\fP to terminate before returning
+its status, instead of returning when it changes status.
If
.I id
specifies a non-existent process or job, the return status is
/* redir.c -- Functions to perform input and output redirection. */
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
+/* Copyright (C) 1997-2019 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
# include "input.h"
#endif
+#include "builtins/pipesize.h"
+
+/* Normally set by a build process command that computes pipe capacity */
+#ifndef PIPESIZE
+# ifdef PIPE_BUF
+# define PIPESIZE PIPE_BUF
+# else
+# define PIPESIZE 4096
+# endif
+#endif
+
#define SHELL_FD_BASE 10
int expanding_redir;
static int undoablefd __P((int));
static int do_redirection_internal __P((REDIRECT *, int));
-static int write_here_document __P((int, WORD_DESC *));
-static int write_here_string __P((int, WORD_DESC *));
+static char *heredoc_expand __P((WORD_DESC *, enum r_instruction, size_t *));
+static int heredoc_write __P((int, char *, size_t));
static int here_document_to_fd __P((WORD_DESC *, enum r_instruction));
static int redir_special_open __P((int, char *, int, int, enum r_instruction));
return (result);
}
-static int
-write_here_string (fd, redirectee)
- int fd;
+/* Expand a here-document or here-string (determined by RI) contained in
+ REDIRECTEE and return the expanded document. If LENP is non-zero, put
+ the length of the returned string into *LENP.
+
+ This captures everything about expanding here-documents and here-strings:
+ the returned document should be written directly to whatever file
+ descriptor is specified. In particular, it adds a newline to the end of
+ a here-string to preserve previous semantics. */
+static char *
+heredoc_expand (redirectee, ri, lenp)
WORD_DESC *redirectee;
+ enum r_instruction ri;
+ size_t *lenp;
{
- char *herestr;
- int herelen, n, e, old;
+ char *document;
+ size_t dlen;
+ int old;
+
+ if (redirectee->word == 0 || redirectee->word[0] == '\0')
+ {
+ if (lenp)
+ *lenp = 0;
+ return (redirectee->word);
+ }
+ /* Quoted here documents are not expanded */
+ if (ri != r_reading_string && (redirectee->flags & W_QUOTED))
+ {
+ if (lenp)
+ *lenp = STRLEN (redirectee->word);
+ return (redirectee->word);
+ }
+
expanding_redir = 1;
/* Now that we've changed the variable search order to ignore the temp
environment, see if we need to change the cached IFS values. */
sv_ifs ("IFS");
- herestr = expand_string_unsplit_to_string (redirectee->word, 0);
+ document = (ri == r_reading_string) ? expand_string_unsplit_to_string (redirectee->word, 0)
+ : expand_string_to_string (redirectee->word, Q_HERE_DOCUMENT);
expanding_redir = 0;
/* Now we need to change the variable search order back to include the temp
environment. We force the temp environment search by forcing
sv_ifs ("IFS");
executing_builtin = old;
- herelen = STRLEN (herestr);
-
- n = write (fd, herestr, herelen);
- if (n == herelen)
+ dlen = STRLEN (document);
+ /* XXX - Add trailing newline to here-string */
+ if (ri == r_reading_string)
{
- n = write (fd, "\n", 1);
- herelen = 1;
+ document = xrealloc (document, dlen + 2);
+ document[dlen++] = '\n';
+ document[dlen] = '\0';
}
+ if (lenp)
+ *lenp = dlen;
+
+ return document;
+}
+
+/* Write HEREDOC (of length HDLEN) to FD, returning 0 on success and ERRNO on
+ error. Don't handle interrupts. */
+static int
+heredoc_write (fd, heredoc, herelen)
+ int fd;
+ char *heredoc;
+ size_t herelen;
+{
+ ssize_t nw;
+ int e;
+
+ errno = 0;
+ nw = write (fd, heredoc, herelen);
e = errno;
- FREE (herestr);
- if (n != herelen)
+ if (nw != herelen)
{
if (e == 0)
e = ENOSPC;
return e;
}
return 0;
-}
+}
-/* Write the text of the here document pointed to by REDIRECTEE to the file
- descriptor FD, which is already open to a temp file. Return 0 if the
- write is successful, otherwise return errno. */
+/* Create a temporary file or pipe holding the text of the here document
+ pointed to by REDIRECTEE, and return a file descriptor open for reading
+ to it. Return -1 on any error, and make sure errno is set appropriately. */
static int
-write_here_document (fd, redirectee)
- int fd;
+here_document_to_fd (redirectee, ri)
WORD_DESC *redirectee;
+ enum r_instruction ri;
{
+ char *filename;
+ int r, fd, fd2, herepipe[2];
char *document;
- int document_len, fd2, old;
- FILE *fp;
- register WORD_LIST *t, *tlist;
+ size_t document_len;
- /* Expand the text if the word that was specified had
- no quoting. The text that we expand is treated
- exactly as if it were surrounded by double quotes. */
+ /* Expand the here-document/here-string first and then decide what to do. */
+ document = heredoc_expand (redirectee, ri, &document_len);
- if (redirectee->flags & W_QUOTED)
+ /* If we have a zero-length document, don't mess with a temp file */
+ if (document_len == 0)
{
- document = redirectee->word;
- document_len = strlen (document);
- /* Set errno to something reasonable if the write fails. */
- if (write (fd, document, document_len) < document_len)
- {
- if (errno == 0)
- errno = ENOSPC;
- return (errno);
- }
- else
- return 0;
+ fd = open ("/dev/null", O_RDONLY);
+ r = errno;
+ if (document != redirectee->word)
+ FREE (document);
+ errno = r;
+ return fd;
}
- expanding_redir = 1;
- /* Now that we've changed the variable search order to ignore the temp
- environment, see if we need to change the cached IFS values. */
- sv_ifs ("IFS");
- tlist = expand_string (redirectee->word, Q_HERE_DOCUMENT);
- expanding_redir = 0;
- /* Now we need to change the variable search order back to include the temp
- environment. We force the temp environment search by forcing
- executing_builtin to 1. This is what makes `read' get the right values
- for the IFS-related cached variables, for example. */
- old = executing_builtin;
- executing_builtin = 1;
- sv_ifs ("IFS");
- executing_builtin = old;
-
- if (tlist)
+#if defined (PIPESIZE)
+ /* Try to use a pipe internal to this process if the document is shorter
+ than the system's pipe capacity (computed at build time). We want to
+ write the entire document without write blocking. */
+ if (document_len <= PIPESIZE)
{
- /* Try using buffered I/O (stdio) and writing a word
- at a time, letting stdio do the work of buffering
- for us rather than managing our own strings. Most
- stdios are not particularly fast, however -- this
- may need to be reconsidered later. */
- if ((fd2 = dup (fd)) < 0 || (fp = fdopen (fd2, "w")) == NULL)
- {
- old = errno;
- if (fd2 >= 0)
- close (fd2);
- dispose_words (tlist);
- errno = old;
- return (errno);
- }
- errno = 0;
- for (t = tlist; t; t = t->next)
+ if (pipe (herepipe) < 0)
{
- /* This is essentially the body of
- string_list_internal expanded inline. */
- document = t->word->word;
- document_len = strlen (document);
- if (t != tlist)
- putc (' ', fp); /* separator */
- fwrite (document, document_len, 1, fp);
- if (ferror (fp))
- {
- if (errno == 0)
- errno = ENOSPC;
- fd2 = errno;
- fclose(fp);
- dispose_words (tlist);
- return (fd2);
- }
+ r = errno;
+ if (document != redirectee->word)
+ free (document);
+ errno = r;
+ return (-1);
}
- dispose_words (tlist);
- if (fclose (fp) != 0)
+ r = heredoc_write (herepipe[1], document, document_len);
+ if (document != redirectee->word)
+ free (document);
+ close (herepipe[1]);
+ if (r) /* write error */
{
- if (errno == 0)
- errno = ENOSPC;
- return (errno);
+ close (herepipe[0]);
+ errno = r;
+ return (-1);
}
+ return (herepipe[0]);
}
- return 0;
-}
-
-/* Create a temporary file holding the text of the here document pointed to
- by REDIRECTEE, and return a file descriptor open for reading to the temp
- file. Return -1 on any error, and make sure errno is set appropriately. */
-static int
-here_document_to_fd (redirectee, ri)
- WORD_DESC *redirectee;
- enum r_instruction ri;
-{
- char *filename;
- int r, fd, fd2;
+#endif
fd = sh_mktmpfd ("sh-thd", MT_USERANDOM|MT_USETMPDIR, &filename);
/* If we failed for some reason other than the file existing, abort */
if (fd < 0)
{
+ r = errno;
FREE (filename);
+ if (document != redirectee->word)
+ FREE (document);
+ errno = r;
return (fd);
}
SET_CLOSE_ON_EXEC (fd);
errno = r = 0; /* XXX */
- /* write_here_document returns 0 on success, errno on failure. */
- if (redirectee->word)
- r = (ri != r_reading_string) ? write_here_document (fd, redirectee)
- : write_here_string (fd, redirectee);
+ r = heredoc_write (fd, document, document_len);
+ if (document != redirectee->word)
+ FREE (document);
if (r)
{
projects / thirdparty / bash.git / commitdiff
