scripts/config: use sed's POSIX interface
PATCH 1/1 scripts/config: use sed's POSIX interface
Script config' relies on extensions of GNU sed', and is thus not working on all Unixes:
- in-place edition of files (-i), which can be replaced with a temporary file;
- extended-regexps (-r), which can be split into basic regexps;
- single-line calls to `a' command, while some implementations require a leading newline before the parameter.
Rewrite calls to `sed' program to comply with POSIX interface.
--- scripts/config | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
scripts/config +9 -3
@@ -66,9 +66,14 @@ set_var() { name_re="^($name=|# $name is not set)" before_re="^($before=|# $before is not set)" if test -n "$before" && grep -Eq "$before_re" "$FN"; then - sed -ri "/$before_re/a $new" "$FN" + lf=$'\n' + sed -e "/^$before=/a\\$lf$new$lf" \ + -e "/^# $before is not set/a\\$lf$new$lf" "$FN" >"$FN.swp" + mv "$FN.swp" "$FN" elif grep -Eq "$name_re" "$FN"; then - sed -ri "s:$name_re.*:$new:" "$FN" + sed -e "s:^$name=.*:$new:" \ + -e "s:^# $name is not set:$new:" "$FN" >"$FN.swp" + mv "$FN.swp" "$FN" else echo "$new" >>"$FN" fi
@@ -77,7 +82,8 @@ set_var() { undef_var() { local name=$1 - sed -ri "/^($name=|# $name is not set)/d" "$FN" + sed -e "/^$name=/d" -e "/^# $name is not set/d" "$FN" >"$FN.swp" + mv "$FN.swp" "$FN" } if [ "$1" = "--file" ]; then
Signature · 1 line
1.8.3.rc1.44.gb387c77.dirty
Clément, All,
On 2013-07-10 21:58 +0200, Clement Chauplannaz spake thusly:
Quoted 9 lines
Script
config' relies on extensions ofGNU sed', and is thus not working on all Unixes:
- in-place edition of files (-i), which can be replaced with a temporary file;
- extended-regexps (-r), which can be split into basic regexps;
- single-line calls to `a' command, while some implementations require a leading newline before the parameter.Rewrite calls to `sed' program to comply with POSIX interface.
Clément, sorry I did not come back to you earlier after your second PM. Here is further review:
Quoted 10 lines
Signed-off-by Clement Chauplannaz <[email protected]>--- scripts/config | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)scripts/config +0
-0
scripts/config set_var() { · line 69
Quoted 5 lines
scripts/config +1
-1@@ -66,9 +66,14 @@ set_var() { name_re="^($name=|# $name is not set)" before_re="^($before=|# $before is not set)" if test -n "$before" && grep -Eq "$before_re" "$FN"; then - sed -ri "/$before_re/a $new" "$FN" + lf=$'\n'
As you explained me earlier, you expect this to actually set the '\n' symbol (0x0a) as first char of variable 'lf'. This is a bashism, and is not POSIX. Here is a test script:
#!/bin/dash
lf=$'\n'
printf "lf='%s'\n" "${lf}"
printf "lf='${lf}'\n"And the output:
lf='$\n'
lf='$
'Now, if you use #!/bin/bash, it works as you expect, but not with a POSIX-only script like dash.
A reliable way to get a single '\n' would be:
lf="$( printf '\n' )"
Yes, config is already a bash script, but no need to add bashisms when they can be avoided. And since this patch is about POSIX compliance in the first place... ;-)
Otherwise, LGTM.
Regards,
Yann E. MORIN.
Signature · 6 lines
.-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'
Yann
2013/7/10 Yann E. MORIN <[email protected]>:
Quoted 46 lines
Clément, All,
On 2013-07-10 21:58 +0200, Clement Chauplannaz spake thusly:
Quoted 9 lines
Script
config' relies on extensions ofGNU sed', and is thus not working on all Unixes:
- in-place edition of files (-i), which can be replaced with a temporary file;
- extended-regexps (-r), which can be split into basic regexps;
- single-line calls to `a' command, while some implementations require a leading newline before the parameter.Rewrite calls to `sed' program to comply with POSIX interface.
Clément, sorry I did not come back to you earlier after your second PM. Here is further review:
Quoted 10 lines
Signed-off-by Clement Chauplannaz <[email protected]>--- scripts/config | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)scripts/config +0
-0scripts/config set_var() { · line 69
Quoted 5 lines
scripts/config +1
-1@@ -66,9 +66,14 @@ set_var() { name_re="^($name=|# $name is not set)" before_re="^($before=|# $before is not set)" if test -n "$before" && grep -Eq "$before_re" "$FN"; then - sed -ri "/$before_re/a $new" "$FN" + lf=$'\n'As you explained me earlier, you expect this to actually set the '\n' symbol (
0x0a) as first char of variable 'lf'. This is a bashism, and is not POSIX. Here is a test script:#!/bin/dash lf=$'\n' printf "lf='%s'\n" "${lf}" printf "lf='${lf}'\n"And the output:
lf='$\n' lf='$ '
Quoted 6 lines
Now, if you use #!/bin/bash, it works as you expect, but not with a POSIX-only script like dash.
A reliable way to get a single '\n' would be:
lf="$( printf '\n' )"
This looks like a good idea. I need to work it more in depth though, as the "single-newline" printf seems to get caught by bash as an IFS - in other words, it produces an empty var. I'll come back to you with my findings.
Quoted 4 lines
Yes, config is already a bash script, but no need to add bashisms when they can be avoided. And since this patch is about POSIX compliance in the first place... ;-)
Well, it's more about POSIX compliance for utilities (grep, sed, find, etc.) which share the same name, a somewhat loose common interface, but a different implementation between GNU & *BSD. I'm assuming bash under Linux and *BSD comes from the same source :-). Besides, I can't say to what extent `config' script complies with POSIX shell interface and how it would run under other shells...
Quoted 3 lines
Otherwise, LGTM.
Best regards,
Clement
Quoted 10 lines
Regards,
Yann E. MORIN.--
.-----------------.--------------------.------------------.--------------------.| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |'------------------------------^-------^------------------^--------------------'