From d890583ecccd1a035cd609a19ff910af8c797b7e Mon Sep 17 00:00:00 2001 From: Ethan Pini Date: Sat, 27 Jun 2026 20:46:46 -0700 Subject: [PATCH 3/3] non-blocking write instead of limiting HEREDOC_PIPESIZE on Mac --- configure | 2 +- configure.ac | 2 +- general.c | 15 +++++++++++++++ general.h | 1 + redir.c | 22 ++++++++++++++++++++++ 5 files changed, 40 insertions(+), 2 deletions(-) diff --git a/configure b/configure index e1b3547d..037eeed4 100755 --- a/configure +++ b/configure @@ -23133,7 +23133,7 @@ hpux*) LOCAL_CFLAGS="-DHPUX -DTGETENT_BROKEN -DTGETFLAG_BROKEN" ;; dgux*) LOCAL_CFLAGS=-D_DGUX_SOURCE; LOCAL_LIBS=-ldgc ;; isc*) LOCAL_CFLAGS=-Disc386 ;; rhapsody*) LOCAL_CFLAGS=-DRHAPSODY ;; -darwin*) LOCAL_CFLAGS="-DMACOSX -DHEREDOC_PIPESIZE=512";; +darwin*) LOCAL_CFLAGS="-DMACOSX -DPIPESIZE_DYNAMIC";; sco3.2v5*) LOCAL_CFLAGS="-b elf -DWAITPID_BROKEN -DPATH_MAX=1024" ;; sco3.2v4*) LOCAL_CFLAGS="-DMUST_UNBLOCK_CHLD -DPATH_MAX=1024" ;; sco3.2*) LOCAL_CFLAGS=-DMUST_UNBLOCK_CHLD ;; diff --git a/configure.ac b/configure.ac index 0b9adc8f..b53aa1d2 100644 --- a/configure.ac +++ b/configure.ac @@ -1209,7 +1209,7 @@ hpux*) LOCAL_CFLAGS="-DHPUX -DTGETENT_BROKEN -DTGETFLAG_BROKEN" ;; dgux*) LOCAL_CFLAGS=-D_DGUX_SOURCE; LOCAL_LIBS=-ldgc ;; isc*) LOCAL_CFLAGS=-Disc386 ;; rhapsody*) LOCAL_CFLAGS=-DRHAPSODY ;; -darwin*) LOCAL_CFLAGS="-DMACOSX -DHEREDOC_PIPESIZE=512";; +darwin*) LOCAL_CFLAGS="-DMACOSX -DPIPESIZE_DYNAMIC";; sco3.2v5*) LOCAL_CFLAGS="-b elf -DWAITPID_BROKEN -DPATH_MAX=1024" ;; sco3.2v4*) LOCAL_CFLAGS="-DMUST_UNBLOCK_CHLD -DPATH_MAX=1024" ;; sco3.2*) LOCAL_CFLAGS=-DMUST_UNBLOCK_CHLD ;; diff --git a/general.c b/general.c index aeffda5c..abd32ab1 100644 --- a/general.c +++ b/general.c @@ -609,6 +609,21 @@ sh_validfd (int fd) return (fcntl (fd, F_GETFD, 0) >= 0); } +/* Set O_NONBLOCK on file descriptor FD. */ +int +sh_setnonblock (int fd) +{ + int fl; + + fl = fcntl (fd, F_GETFL, 0); + if (fl < 0) + { + return fl; + } + + return fcntl (fd, F_SETFL, fl | O_NONBLOCK); +} + int fd_ispipe (int fd) { diff --git a/general.h b/general.h index 5b1eac08..2c936a3b 100644 --- a/general.h +++ b/general.h @@ -318,6 +318,7 @@ extern int assignment (const char *, int); extern int sh_unset_nodelay_mode (int); extern int sh_setclexec (int); +extern int sh_setnonblock (int); extern int sh_validfd (int); extern int fd_ispipe (int); extern void check_dev_tty (void); diff --git a/redir.c b/redir.c index 343536b7..da11bba9 100644 --- a/redir.c +++ b/redir.c @@ -472,7 +472,29 @@ here_document_to_fd (WORD_DESC *redirectee, enum r_instruction ri) } #endif +#if defined (PIPESIZE_DYNAMIC) + /* Pipe capacity may be smaller than detected at build time. Set + O_NONBLOCK on the write end and make a best-effort attempt, + falling back to a tempfile if it would otherwise block. */ + if (sh_setnonblock (herepipe[1]) < 0) + { + close (herepipe[0]); + close (herepipe[1]); + goto use_tempfile; + } +#endif + r = heredoc_write (herepipe[1], document, document_len); + +#if defined (PIPESIZE_DYNAMIC) + if (r == ENOSPC /* set by heredoc_write if written != herelen */) + { + close (herepipe[0]); + close (herepipe[1]); + goto use_tempfile; + } +#endif + if (document != redirectee->word) free (document); close (herepipe[1]); -- 2.49.0