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authorMark Whitley2001-03-03 00:44:55 +0000
committerMark Whitley2001-03-03 00:44:55 +0000
commit9ead68975c05100e4d1fda0b750fbc3688e68cfd (patch)
treeae3a45ace62693d2b64c9aa1e7248f710de38fb4 /docs/style-guide.txt
parent323434be429554d41f3f4764c34fd85bfbeed79a (diff)
downloadbusybox-9ead68975c05100e4d1fda0b750fbc3688e68cfd.zip
busybox-9ead68975c05100e4d1fda0b750fbc3688e68cfd.tar.gz
Added some words on use of getopt in applets.
Diffstat (limited to 'docs/style-guide.txt')
-rw-r--r--docs/style-guide.txt46
1 files changed, 45 insertions, 1 deletions
diff --git a/docs/style-guide.txt b/docs/style-guide.txt
index 1f06662..b4c3bac 100644
--- a/docs/style-guide.txt
+++ b/docs/style-guide.txt
@@ -26,7 +26,9 @@ Here is the order in which code should be laid out in a file:
- commented author name and email address(es)
- commented GPL boilerplate
- commented longer description / notes for the program (if needed)
- - #includes and #defines
+ - #includes of .h files with angle brackets (<>) around them
+ - #includes of .h files with quotes ("") around them
+ - #defines (if any, note the section below titled "Avoid the Preprocessor")
- const and global variables
- function declarations (if necessary)
- function implementations
@@ -607,3 +609,45 @@ illustrates emphasizing logical blocks:
/* clean up */
free(line);
}
+
+
+Processing Options with getopt
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If your applet needs to process command-line switches, please use getopt() to
+do so. Numerous examples can be seen in many of the existing applets, but
+basically it boils down to two things: at the top of the .c file, have this
+line in the midst of your #includes:
+
+ #include <getopt.h>
+
+And a code block similar to the following near the top of your applet_main()
+routine:
+
+ while ((opt = getopt(argc, argv, "abc")) > 0) {
+ switch (opt) {
+ case 'a':
+ do_a_opt = 1;
+ break;
+ case 'b':
+ do_b_opt = 1;
+ break;
+ case 'c':
+ do_c_opt = 1;
+ break;
+ default:
+ show_usage(); /* in utility.c */
+ }
+ }
+
+If your applet takes no options (such as 'init'), there should be a line
+somewhere in the file reads:
+
+ /* no options, no getopt */
+
+That way, when people go grepping to see which applets need to be converted to
+use getopt, they won't get false positives.
+
+Additional Note: Do not use the getopt_long library function and do not try to
+hand-roll your own long option parsing. Busybox applets should only support
+short options, plus explanations and examples in usage.h.