This is just a proof of concept. I'd like to know this approach may be
accepted.
It helps avoid manual aligning of help text, which is boring
(e.g. chmod's --no-preserve-root does it wrong) and impossible to do
right for shared options such as --verbose and --help.
It also helps avoid misalignment in translations because translators may
not notice that the number of spaces in such a translations has a special
meaning.
The convenient function may end up in gnulib, I don't know.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
lib/Makefile.am | 2 +-
lib/usage.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/usage.h | 4 ++++
src/chmod.c | 40 ++++++++++++++++++--------------
4 files changed, 100 insertions(+), 18 deletions(-)
create mode 100644 lib/usage.c
create mode 100644 lib/usage.h
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 885f9b2..d8851af 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -31,7 +31,7 @@ include gnulib.mk
AM_CFLAGS += $(GNULIB_WARN_CFLAGS) $(WERROR_CFLAGS)
libcoreutils_a_SOURCES += \
- buffer-lcm.c buffer-lcm.h
+ buffer-lcm.c buffer-lcm.h usage.c
libcoreutils_a_LIBADD += $(LIBOBJS)
libcoreutils_a_DEPENDENCIES += $(LIBOBJS)
diff --git a/lib/usage.c b/lib/usage.c
new file mode 100644
index 0000000..e2ecc00
--- /dev/null
+++ b/lib/usage.c
@@ -0,0 +1,72 @@
+#include <config.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <gettext.h>
+#include "xalloc.h"
+
+#define _(msgid) gettext (msgid)
+
+int print_usage(const char **help)
+{
+ int i;
+ int arg_len = 0;
+ char *buf;
+
+ for (i = 0; help[i]; i++)
+ {
+ const char *h = _(help[i]);
+ int len;
+ if (i % 2)
+ continue;
+ len = h[0] == '-' && h[1] == '-' ? 4 : 0;
+ len += strlen (h);
+ if (len > arg_len)
+ arg_len = len;
+ }
+
+ arg_len += 4; /* two leading and trailing spaces */
+ buf = xmalloc (arg_len + 1);
+ memset (buf, ' ', arg_len);
+ buf[arg_len] = '\0';
+
+ for (i = 0; help[i]; i += 2)
+ {
+ const char *a = _(help[i]);
+ const char *h = _(help[i + 1]);
+ int p = 2;
+
+ if (!h)
+ {
+ free (buf);
+ return -1;
+ }
+
+ if (a[0] == '-' && a[1] == '-')
+ p += 4;
+ memcpy (buf + p, a, strlen (a));
+ fputs (buf, stdout);
+ memset (buf, ' ', arg_len);
+
+ while (*h)
+ {
+ const char *newline = strchr (h, '\n');
+ if (newline)
+ {
+ fwrite (h, newline + 1 - h, 1, stdout);
+ fputs (buf, stdout);
+ h = newline + 1;
+ }
+ else
+ {
+ fputs (h, stdout);
+ break;
+ }
+ }
+ fputs ("\n", stdout);
+ }
+
+ free (buf);
+
+ return 0;
+}
diff --git a/lib/usage.h b/lib/usage.h
new file mode 100644
index 0000000..64e3bc0
--- /dev/null
+++ b/lib/usage.h
@@ -0,0 +1,4 @@
+#ifndef __USAGE_H__
+#define __USAGE_H__
+extern int print_usage(const char **help);
+#endif
diff --git a/src/chmod.c b/src/chmod.c
index a54078c..5e790a3 100644
--- a/src/chmod.c
+++ b/src/chmod.c
@@ -31,6 +31,7 @@
#include "quotearg.h"
#include "root-dev-ino.h"
#include "xfts.h"
+#include "usage.h"
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "chmod"
@@ -107,6 +108,27 @@ static struct option const long_options[] =
{NULL, 0, NULL, 0}
};
+static const char *option_help[] =
+{
+ N_("-c, --changes"),
+ N_("like --verbose but report only when a change is made"),
+ N_("-f, --silent, --quiet"),
+ N_("suppress most error messages"),
+ N_("-v, --verbose"),
+ N_("output a diagnostic for every file processed"),
+ N_("--no-preserve-root"),
+ N_("do not treat '/' specially (the default)"),
+ N_("--preserve-root"),
+ N_("fail to operate recursively on '/'"),
+ N_("--reference=RFILE"),
+ N_("use RFILE's mode instead of MODE values"),
+ N_("-R, --recursive"),
+ N_("change files and directories recursively"),
+ N_("--help"), N_("display this help and exit"),
+ N_("--version"), N_("output version information and exit"),
+ NULL
+};
+
/* Return true if the chmodable permission bits of FILE changed.
The old mode was OLD_MODE, but it was changed to NEW_MODE. */
@@ -379,23 +401,7 @@ Change the mode of each FILE to MODE.\n\
With --reference, change the mode of each FILE to that of RFILE.\n\
\n\
"), stdout);
- fputs (_("\
- -c, --changes like verbose but report only when a change is made\n\
- -f, --silent, --quiet suppress most error messages\n\
- -v, --verbose output a diagnostic for every file processed\n\
-"), stdout);
- fputs (_("\
- --no-preserve-root do not treat '/' specially (the default)\n\
- --preserve-root fail to operate recursively on '/'\n\
-"), stdout);
- fputs (_("\
- --reference=RFILE use RFILE's mode instead of MODE values\n\
-"), stdout);
- fputs (_("\
- -R, --recursive change files and directories recursively\n\
-"), stdout);
- fputs (HELP_OPTION_DESCRIPTION, stdout);
- fputs (VERSION_OPTION_DESCRIPTION, stdout);
+ print_usage (option_help);
fputs (_("\
\n\
Each MODE is of the form '[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'.\n\
--
1.7.12.rc2.18.g61b472e
