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This commit is contained in:
Chet Ramey
2021-06-01 11:30:37 -04:00
parent 2047e28584
commit 6e11792d93
7 changed files with 2018 additions and 2012 deletions
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CWRU/CWRU.chlog
+33
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@@ -10451,3 +10451,36 @@ parse.y
setting it unconditionally. Report and patch from
Vincent Menegaux <vincent.menegaux@gmail.com> via
https://savannah.gnu.org/patch/?10070
5/25
----
doc/{bash.1,bashref.texi}
- test: add the ( $2 $3 ) case to the description of the four-argument
behavior. Inspired by a discussion with Christoph Anton Mitterer
<calestyo@scientia.net>
5/27
----
doc/bashref.texi
- replace most of the GNU parallel section with a reference to the
tutorial on gnu.org
lib/glob/glob.h
- GX_NEGATE: new flag; indicates whether the pattern is being negated
as part of an extglob pattern. Not used yet
lib/glob/glob.c
- extglob_skipname,wextglob_skipname: pass GX_NEGATE to the skipname
functions if the pattern is being negated. Not checked yet
5/28
----
doc/{bash.1,bashref.texi}
- dotglob: add text to clarify that `.' and `..' have to be matched by
a pattern beginning with `.' or -- and this is the sketchy part --
that a pattern beginning with `.' has to be one of the patterns in
an extended glob expression
lib/glob/glob.c
- skipname,wskipname: perform the special checks for `.' only if the
pattern is not being negated
doc/bash.0
+1548 -1512
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doc/bash.1
+11 -2
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@@ -3691,10 +3691,14 @@ The filenames
.B ``.''
and
.B ``..''
must always be matched explicitly, even if
must always be matched
by a pattern beginning with ``.'' (for example, ``.?''),
or a pattern beginning with ``.'' must be one of the patterns in an
extended pattern matching expression (see below),
even if
.B dotglob
is set.
In other cases, the
When not matching pathnames, the
.B ``.''
character is not treated specially.
When matching a pathname, the slash character must always be
@@ -10491,8 +10495,13 @@ argument.
Otherwise, the expression is false.
.TP
4 arguments
The following conditions are applied in the order listed.
If the first argument is \fB!\fP, the result is the negation of
the three-argument expression composed of the remaining arguments.
the two-argument test using the second and third arguments.
If the first argument is exactly \fB(\fP and the fourth argument is
exactly \fB)\fP, the result is the two-argument test of the second
and third arguments.
Otherwise, the expression is parsed and evaluated according to
precedence using the rules listed above.
.TP
doc/bashref.info
+349 -369
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File diff suppressed because it is too large Load Diff
doc/bashref.texi
+19 -114
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@@ -1487,117 +1487,9 @@ Parallel provides shorthand references to many of the most common operations
the input source, and so on). Parallel can replace @code{xargs} or feed
commands from its input sources to several different instances of Bash.
For a complete description, refer to the GNU Parallel documentation. A few
examples should provide a brief introduction to its use.
For example, it is easy to replace @code{xargs} to gzip all html files in the
current directory and its subdirectories:
@example
find . -type f -name '*.html' -print | parallel gzip
@end example
@noindent
If you need to protect special characters such as newlines in file names,
use find's @option{-print0} option and parallel's @option{-0} option.
You can use Parallel to move files from the current directory when the
number of files is too large to process with one @code{mv} invocation:
@example
printf '%s\n' * | parallel mv @{@} destdir
@end example
As you can see, the @{@} is replaced with each line read from standard input.
While using @code{ls} will work in most instances, it is not sufficient to
deal with all filenames. @code{printf} is a shell builtin, and therefore is
not subject to the kernel's limit on the number of arguments to a program,
so you can use @samp{*} (but see below about the @code{dotglob} shell option).
If you need to accommodate special characters in filenames, you can use
@example
printf '%s\0' * | parallel -0 mv @{@} destdir
@end example
@noindent
as alluded to above.
This will run as many @code{mv} commands as there are files in the current
directory.
You can emulate a parallel @code{xargs} by adding the @option{-X} option:
@example
printf '%s\0' * | parallel -0 -X mv @{@} destdir
@end example
(You may have to modify the pattern if you have the @code{dotglob} option
enabled.)
GNU Parallel can replace certain common idioms that operate on lines read
from a file (in this case, filenames listed one per line):
@example
while IFS= read -r x; do
do-something1 "$x" "config-$x"
do-something2 < "$x"
done < file | process-output
@end example
@noindent
with a more compact syntax reminiscent of lambdas:
@example
cat list | parallel "do-something1 @{@} config-@{@} ; do-something2 < @{@}" |
process-output
@end example
Parallel provides a built-in mechanism to remove filename extensions, which
lends itself to batch file transformations or renaming:
@example
ls *.gz | parallel -j+0 "zcat @{@} | bzip2 >@{.@}.bz2 && rm @{@}"
@end example
@noindent
This will recompress all files in the current directory with names ending
in .gz using bzip2, running one job per CPU (-j+0) in parallel.
(We use @code{ls} for brevity here; using @code{find} as above is more
robust in the face of filenames containing unexpected characters.)
Parallel can take arguments from the command line; the above can also be
written as
@example
parallel "zcat @{@} | bzip2 >@{.@}.bz2 && rm @{@}" ::: *.gz
@end example
If a command generates output, you may want to preserve the input order in
the output. For instance, the following command
@example
@{
echo foss.org.my ;
echo debian.org ;
echo freenetproject.org ;
@} | parallel traceroute
@end example
@noindent
will display as output the traceroute invocation that finishes first.
Adding the @option{-k} option
@example
@{
echo foss.org.my ;
echo debian.org ;
echo freenetproject.org ;
@} | parallel -k traceroute
@end example
@noindent
will ensure that the output of @code{traceroute foss.org.my} is displayed first.
Finally, Parallel can be used to run a sequence of shell commands in parallel,
similar to @samp{cat file | bash}.
It is not uncommon to take a list of filenames, create a series of shell
commands to operate on them, and feed that list of commands to a shell.
Parallel can speed this up. Assuming that @file{file} contains a list of
shell commands, one per line,
@example
parallel -j 10 < file
@end example
@noindent
will evaluate the commands using the shell (since no explicit command is
supplied as an argument), in blocks of ten shell jobs at a time.
For a complete description, refer to the GNU Parallel documentation, which
is available at
@url{https://www.gnu.org/software/parallel/parallel_tutorial.html}.
@node Shell Functions
@section Shell Functions
@@ -2769,9 +2661,12 @@ without regard to the case of alphabetic characters.
When a pattern is used for filename expansion, the character @samp{.}
at the start of a filename or immediately following a slash
must be matched explicitly, unless the shell option @code{dotglob} is set.
The filenames @samp{.} and @samp{..} must always be matched explicitly,
The filenames @samp{.} and @samp{..} must be matched
by a pattern beginning with @samp{.} (for example, @samp{.?}),
or a pattern beginning with @samp{.} must be one of the patterns in an
extended pattern matching expression (see below),
even if @code{dotglob} is set.
In other cases, the @samp{.} character is not treated specially.
When not matching filenames, the @samp{.} character is not treated specially.
When matching a filename, the slash character must always be
matched explicitly by a slash in the pattern, but in other matching
@@ -4096,10 +3991,20 @@ Otherwise, the expression is false.
@end enumerate
@item 4 arguments
The following conditions are applied in the order listed.
@enumerate
@item
If the first argument is @samp{!}, the result is the negation of
the three-argument expression composed of the remaining arguments.
@item
If the first argument is exactly @samp{(} and the fourth argument is
exactly @samp{)}, the result is the two-argument test of the second
and third arguments.
@item
Otherwise, the expression is parsed and evaluated according to
precedence using the rules listed above.
@end enumerate
@item 5 or more arguments
The expression is parsed and evaluated according to precedence
@@ -4601,7 +4506,7 @@ each builtin with an indication of whether or not it is enabled.
The @option{-f} option means to load the new builtin command @var{name}
from shared object @var{filename}, on systems that support dynamic loading.
Bash will use the value of the @enable{BASH_LOADABLES_PATH} variable as a
Bash will use the value of the @env{BASH_LOADABLES_PATH} variable as a
colon-separated list of directories in which to search for @var{filename}.
The default is system-dependent.
The @option{-d} option will delete a builtin loaded with @option{-f}.
lib/glob/glob.c
+57 -15
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@@ -201,7 +201,7 @@ extglob_skipname (pat, dname, flags)
int flags;
{
char *pp, *pe, *t, *se;
int n, r, negate, wild, nullpat;
int n, r, negate, wild, nullpat, xflags;
negate = *pat == '!';
wild = *pat == '*' || *pat == '?';
@@ -213,12 +213,17 @@ extglob_skipname (pat, dname, flags)
if (pe == 0)
return 0;
xflags = flags | ( negate ? GX_NEGATE : 0);
/* if pe != se we have more of the pattern at the end of the extglob
pattern. Check the easy case first ( */
if (pe == se && *pe == 0 && pe[-1] == ')' && (t = strchr (pp, '|')) == 0)
{
pe[-1] = '\0';
r = XSKIPNAME (pp, dname, flags); /*(*/
/* This is where we check whether the pattern is being negated and
match all files beginning with `.' if the pattern begins with a
literal `.'. */
r = XSKIPNAME (pp, dname, xflags); /*(*/
pe[-1] = ')';
return r;
}
@@ -238,7 +243,7 @@ extglob_skipname (pat, dname, flags)
t[-1] = n; /* no-op for now */
else
t[-1] = '\0';
r = XSKIPNAME (pp, dname, flags);
r = XSKIPNAME (pp, dname, xflags);
t[-1] = n;
if (r == 0) /* if any pattern says not skip, we don't skip */
return r;
@@ -284,15 +289,26 @@ skipname (pat, dname, flags)
DOT_OR_DOTDOT (dname))
return 1;
#if 0
/* This is where we check whether the pattern is being negated and
match all files beginning with `.' if the pattern begins with a
literal `.'. This is the negation of the next clause. */
else if ((flags & GX_NEGATE) && noglob_dot_filenames == 0 &&
dname[0] == '.' &&
(pat[0] == '.' || (pat[0] == '\\' && pat[1] == '.')))
return 0;
#endif
/* If a dot must be explicitly matched, check to see if they do. */
else if (noglob_dot_filenames && dname[0] == '.' && pat[0] != '.' &&
(pat[0] != '\\' || pat[1] != '.'))
else if (noglob_dot_filenames && dname[0] == '.' &&
pat[0] != '.' && (pat[0] != '\\' || pat[1] != '.'))
return 1;
/* Special checks for `.'. The only things that can match `.' are ".",
"\.", ".*", and "\.*". We don't try to match everything here, just
make sure that we don't let something obviously disqualifying by. */
else if (dname[0] == '.' && dname[1] == '\0')
make sure that we don't let something obviously disqualifying by.
We only do this if we're not negating the pattern. */
else if ((flags & GX_NEGATE) == 0 && dname[0] == '.' && dname[1] == '\0')
{
if (pat[0] != '.' && (pat[0] != '\\' || pat[1] != '.'))
return 1;
@@ -301,7 +317,21 @@ skipname (pat, dname, flags)
return 1;
}
/* We don't currently have any additional special checks for `..' */
#if 0
/* These are additional special checks for `..'. We let through "..",
"\..", ".\.", "\.\.", ".*", ".?", "\.*", and "\.?".
Disabled because it doesn't deal with things like `@(.).' at all. */
else if (dname[0] == '.' && dname[1] == '.' && dname[2] == '\0')
{
if (pat[0] != '.' && (pat[0] != '\\' || pat[1] != '.')) /* [\]. */
return 1;
i = (pat[0] == '.') ? 1 : 2;
if (pat[i] && (pat[i] == '*' || pat[i] == '?') && pat[i+1] == '\0')
return 0; /* [\].[*?] */
if (pat[i] != '.' && (pat[i] != '\\' || pat[i+1] != '.')) /* [\].[\]. */
return 1;
}
#endif
return 0;
}
@@ -325,17 +355,27 @@ wskipname (pat, dname, flags)
WDOT_OR_DOTDOT (dname))
return 1;
#if 0
/* This is where we check whether the pattern is being negated and
match all files beginning with `.' if the pattern begins with a
literal `.'. This is the negation of the next clause. */
else if ((flags & GX_NEGATE) && noglob_dot_filenames == 0 &&
dname[0] == L'.' &&
(pat[0] == L'.' || (pat[0] == L'\\' && pat[1] == L'.')))
return 0;
#endif
/* If a leading dot must be explicitly matched, check to see if the
pattern and dirname both have one. */
else if (noglob_dot_filenames && dname[0] == L'.' &&
pat[0] != L'.' &&
(pat[0] != L'\\' || pat[1] != L'.'))
pat[0] != L'.' && (pat[0] != L'\\' || pat[1] != L'.'))
return 1;
/* Special checks for `.'. The only things that can match `.' are ".",
"\.", ".*", and "\.*". We don't try to match everything here, just
make sure that we don't let something obviously disqualifying by. */
else if (dname[0] == L'.' && dname[1] == L'\0')
make sure that we don't let something obviously disqualifying by.
We only do this if we're not negating the pattern. */
else if ((flags & GX_NEGATE) == 0 && dname[0] == L'.' && dname[1] == L'\0')
{
if (pat[0] != L'.' && (pat[0] != L'\\' || pat[1] != L'.'))
return 1;
@@ -354,7 +394,7 @@ wextglob_skipname (pat, dname, flags)
{
#if EXTENDED_GLOB
wchar_t *pp, *pe, *t, *se, n;
int r, negate, wild, nullpat;
int r, negate, wild, nullpat, xflags;
negate = *pat == L'!';
wild = *pat == L'*' || *pat == L'?';
@@ -366,12 +406,14 @@ wextglob_skipname (pat, dname, flags)
if (pe == 0)
return 0;
xflags = flags | ( negate ? GX_NEGATE : 0);
/* if pe != se we have more of the pattern at the end of the extglob
pattern. Check the easy case first ( */
if (pe == se && *pe == L'\0' && pe[-1] == L')' && (t = wcschr (pp, L'|')) == 0)
{
pe[-1] = L'\0';
r = wskipname (pp, dname, flags); /*(*/
r = wskipname (pp, dname, xflags); /*(*/
pe[-1] = L')';
return r;
}
@@ -389,7 +431,7 @@ wextglob_skipname (pat, dname, flags)
t[-1] = n; /* no-op for now */
else
t[-1] = L'\0';
r = wskipname (pp, dname, flags);
r = wskipname (pp, dname, xflags);
t[-1] = n;
if (r == 0)
return 0;
lib/glob/glob.h
+1
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@@ -32,6 +32,7 @@
#define GX_GLOBSTAR 0x400 /* turn on special handling of ** */
#define GX_RECURSE 0x800 /* internal -- glob_filename called recursively */
#define GX_SYMLINK 0x1000 /* internal -- symlink to a directory */
#define GX_NEGATE 0x2000 /* internal -- extglob pattern being negated */
extern int glob_pattern_p PARAMS((const char *));
extern char **glob_vector PARAMS((char *, char *, int));