stdc: some improvements

- Some small stylistic changes such as removing trailing semicolons and noisy shift calls.

- Ensure pcregrep exists. It is installed as pcre2grep on my machine, so check for both and error out if neither is found. Prefer pcre2grep (installed by libpcre2) because libpcre is EOL.

- Make libc_summ() standard-agnostics by passing in the filter expression and the path to the doc as arguments.

- Make libc_summ() error out if the doc is not found.

- Give basic usage information on usage errors.

- Make the standard version match case insensitive.

Signed-off-by Oskari Pirhonen <[email protected]>

---
v1 -> v2:
- Prefer pcre2grep from libpcre2. Suggested by Sam on IRC.

 bin/stdc | 101 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 68 insertions(+), 33 deletions(-)

bin/stdc +0 -0

index 8c725a2..0d322af 100755

bin/stdc +36 -14

 err()
 {
-	>&2 echo "$(basename "$0"): error: $*";
-	exit 1;
+	>&2 echo "$*"
 }
 
-grep_proto()
+die()
+{
+	err "$(basename "$0"): error: $*"
+	exit 1
+}
+
+# Args:
+# 	1: usage error
+usage()
 {
-	pcregrep -M "(?s)\b$1 *\([[:alnum:]*,._\s\(\)-]*\);$";
+	err "$*"
+	err
+	err "usage: $(basename "$0") <version> <function>"
+	err
+	err "    version    ISO C version. Supported versions:"
+	err "               C89, C99, C11"
+	err "               (case insensitive)"
+	err "    function   Function to look for"
+	exit 1
 }
 
-libc_summ_c89()
+# Args:
+# 	1: declaration to look for
+grep_proto()
 {
-	sed -n '/A.3 LIBRARY SUMMARY/,$p' <"$docdir/c/c89/c89-draft.txt";
+	"$pcregrep" -M "(?s)\b$1 *\([[:alnum:]*,._\s\(\)-]*\);\$"
 }
 
+# Args:
+# 	1: filter expression
+# 	2: path to plaintext standard
 libc_summ()
 {
-	sed -n '/Library summary$/,/Sequence points$/p';
+	if [[ ! -r "$2" ]]; then
+		die "cannot find or read '$2'"
+	fi
+	sed -n -e "$1" "$2"
 }
 
+if [[ -z "$pcregrep" ]]; then
+	die "pcre2grep or pcregrep required but is not installed"
+fi
+
 case $# in
-0)
-	err "missing ISO C version.";
-	;;
-1)
-	err "missing function name.";
+0|1)
+	usage "missing ISO C version and/or function name."
 	;;
 2)
 	;;
 *)
-	shift;
-	shift;

bin/stdc +3 -6

 	;;
 c99)
-	shift;
-	libc_summ <"$docdir/c/c99/n1256.txt" \
-	| grep_proto $@;
+	libc_summ "$c99_filter" "$c99_doc" \
+	| grep_proto "$2"
 	;;
 c11)
-	shift;
-	libc_summ <"$docdir/c/c11/n1570.txt" \
-	| grep_proto $@;
+	libc_summ "$c11_filter" "$c11_doc" \

Review

Quoted 2 lines

(quoted diff) +2 -0

+
+# vim: set noexpandtab:

I'm not sure we want vim comments like this one for every file. Aren't they too noisy? But maybe it's just me. I use things like the following for when I contribute regularly to projects that use a different rule for indentation:

Hi Oskari, Sam,

Quoted 2 lines · Oskari Pirhonen

- Some small stylistic changes such as removing trailing semicolons and noisy shift calls.

But they are sooo pretty =) That's a little OCD of mine putting semicolons in shell scripts. Maybe I read too much C, but it feels good to see punctuation marks at the end of sentences. I prefer to keep semicolons.

Quoted 3 lines

- Ensure pcregrep exists. It is installed as pcre2grep on my machine, so check for both and error out if neither is found. Prefer pcre2grep (installed by libpcre2) because libpcre is EOL.

Hmm, I didn't know about pcre2grep(1). I've applied the following:

libc_summ_c89()

Quoted 2 lines

- Make libc_summ() standard-agnostics by passing in the filter expression and the path to the doc as arguments.

It's really standards agnostic except for C89. ISO C drafts are pretty much all the same except for the original one, since I was really ANSI C. That's why C99 and C11 (and C2x if we add it) can reuse libc_summ(), but C89 is an exception.

Quoted 1 line

- Make libc_summ() error out if the doc is not found.

The shell already errors out with a quite readable message:

$ ./bin/stdc c99 fgets
./bin/stdc: line 54: /usr/local/share/doc/c/c99/n1256.foo: No such file or directory
$ echo $?
1

Is it not good enough?

Quoted 1 line

- Give basic usage information on usage errors.

I prefer writing a man page. It keeps the source code simpler. Please keep this suggestion around, and resend it if you feel it's necessary after having a man page (1 or 2 weeks maybe).

Quoted 1 line

- Make the standard version match case insensitive.

Okay.

Quoted 2 lines

Signed-off-by Oskari Pirhonen <[email protected]>

Please send individual patches for each of the logical changes.

Quoted 15 lines

---
v1 -> v2:
- Prefer pcre2grep from libpcre2. Suggested by Sam on IRC.

 bin/stdc | 101 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 68 insertions(+), 33 deletions(-)

bin/stdc +1 -1

index 8c725a2..0d322af 100755
@@ -1,65 +1,100 @@
-#!/bin/bash
+#!/usr/bin/env bash
 

bin/stdc line 3

Quoted 2 lines

bin/stdc +1 -1

-set -Eefuo pipefail;
+set -Efuo pipefail

Why not set -e? It's not documented in the commit message.

bin/stdc line 4

Quoted 3 lines

bin/stdc +1 -1

-case "$1" in
+case "${1@L}" in

I'm not a fan of shell features. I prefer some command like

    "$(printf "%s" "$1" | tr [[:upper:]] [[:lower:]])"

which is much more readable (IMO). Does that look good to you?

Quoted 6 lines

bin/stdc +2 -3

 c89)
-	shift;
-	libc_summ_c89 \
-	| grep_proto $@;
+	libc_summ "$c89_filter" "$c89_doc" \
+	| grep_proto "$2"

bin/stdc

Quoted 3 lines

bin/stdc +3 -0

+esac
+
+# vim: set noexpandtab:

I'm not sure we want vim comments like this one for every file. Aren't they too noisy? But maybe it's just me. I use things like the following for when I contribute regularly to projects that use a different rule for indentation:

au bufnewfile,bufread ~/src/linux/man-pages/*/man*/* setlocal expandtab au bufnewfile,bufread ~/src/linux/man-pages/*/man*/* setlocal shiftwidth=4 au bufnewfile,bufread ~/src/linux/man-pages/*/man*/* setlocal softtabstop=4 au bufnewfile,bufread ~/src/linux/man-pages/*/man*/* setlocal tabstop=5

au bufnewfile,bufread ~/src/nginx/* setlocal expandtab au bufnewfile,bufread ~/src/nginx/* setlocal shiftwidth=4 au bufnewfile,bufread ~/src/nginx/* setlocal softtabstop=4 au bufnewfile,bufread ~/src/nginx/* setlocal tabstop=5

(tabstop=5 is for realizing when something is actually a tab, which for example happens in Makefiles in NGINX.)