Module Name: src Committed By: kre Date: Tue May 18 21:39:06 UTC 2021
Modified Files: src/bin/sh/bltin: bltin.h echo.c Log Message: Fix a bug in the built-in echo in /bin/sh reported in private mail by Oguz <oguzismailuy...@gmail.com> If echo detects an I/O error, it does exit(1) (that's fine) but then the next echo also does exit(1) even without any errors of its own, and every following echo writing to stdout does the same thing. eg: echo foo >&- ; echo $?; echo $?; ( echo $( echo $?; echo $?) ; echo $? ) 1 1 1 1 1 The first echo writes nothing (stdout is closed) but does exit(1). The second echo writes "1" (correct, the exit status of the previous echo) and should exit(0) - but doesn't. This pattern continues... While here, conform to the POSIX requirement on echo (and many other standard utilities, but definitely not all) that when the utility does exit(>0) a message must be written to stderr (and vice versa in many cases). Our echo (as shown above) did the exit(1) part when it detected the I/O error, but no message is sent to stderr. Fix that while we're here. Similar changes are required for /bin/echo (coming soon), and /usr/bin/printf (which is also the sh builtin printf) - except currently that one kind of conforms, as it ignores errors writing to stdout (as do large numbers of other utilities). For many programs that's kind of acceptable, but where the sole purpose of the program is to write to stdout, it really isn't. Also to be fixed soon. To generate a diff of this commit: cvs rdiff -u -r1.15 -r1.16 src/bin/sh/bltin/bltin.h cvs rdiff -u -r1.14 -r1.15 src/bin/sh/bltin/echo.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.