From: Junio C Hamano Date: Tue, 27 Oct 2026 18:38:20 GMT Subject: Re: [PATCH] test-chmtime: use parse_options() to parse command-line flags Message-ID: In-Reply-To: "Shashank S via GitGitGadget" writes: > From: Shashank S Mogaveera > > cmd__chmtime() currently parses the '-v'/'--verbose' and '-g'/'--get' > flags manually using strcmp() checks and manual index tracking. > > Refactor cmd__chmtime() to use parse_options() and usage_with_options() > instead. Pass PARSE_OPT_KEEP_UNKNOWN_OPT so that negative relative time > offsets (such as '-86400') are not rejected as unknown short options > and remain in argv for timespec_arg() to parse. I somehow find the verb "refactor" used to describe a change like this slightly awkward, but it is excellent to reminder readers why it is necessary to use PARSE_OPT_KEEP_UNKNOWN_OPT. > t/helper/test-chmtime.c | 46 +++++++++++++++++++---------------------- > 1 file changed, 21 insertions(+), 25 deletions(-) > > diff --git a/t/helper/test-chmtime.c b/t/helper/test-chmtime.c > index 0e5538833a..dc6281b1d6 100644 > --- a/t/helper/test-chmtime.c > +++ b/t/helper/test-chmtime.c > @@ -38,10 +38,13 @@ > */ > #include "test-tool.h" > #include "git-compat-util.h" > +#include "parse-options.h" > #include > > -static const char usage_str[] = > - "(-v|--verbose|-g|--get) (+|=|=+|=-|-) ..."; > +static const char * const chmtime_usage[] = { > + "test-tool chmtime (-v|--verbose|-g|--get) (+|=|=+|=-|-) ...", > + NULL > +}; Is it necessary to spell out the options like verbose and get, once you switch to the parse-options API? What does "test-tool chmtime -h" say with this patch applied? I think it is common to say [] instead and let the list of options produced by the parse-options API to take it from there. > static int timespec_arg(const char *arg, long int *set_time, int *set_eq) > { > @@ -68,40 +71,37 @@ static int timespec_arg(const char *arg, long int *set_time, int *set_eq) > > int cmd__chmtime(int argc, const char **argv) > { > - static int verbose; > - static int get; > + int verbose = 0; > + int get = 0; There is no reason why these two need to be static, but as a "main()" function for a run-once-and-exit program, there is no reason why they should not be static, either. With this change, you are forced to explicitly initialize them to 0. > - int i = 1; > /* no mtime change by default */ > int set_eq = 0; > long int set_time = 0; > > - if (argc < 3) > - goto usage; > > - if (strcmp(argv[i], "--get") == 0 || strcmp(argv[i], "-g") == 0) { > - get = 1; > - ++i; > - } else if (strcmp(argv[i], "--verbose") == 0 || strcmp(argv[i], "-v") == 0) { > - verbose = 1; > - ++i; > - } > > - if (i == argc) { > - goto usage; > - } > > if (timespec_arg(argv[i], &set_time, &set_eq)) { > ++i; > } else { > if (get == 0 && verbose == 0) { > fprintf(stderr, "Not a base-10 integer: %s\n", argv[i] + 1); > - goto usage; > } > } > > if (i == argc) > - goto usage; > > for (; i < argc; i++) { > struct stat sb; I agree that the original was horrible in that it did not allow -v to come before -g etc. Now, let's read the updated code. > + int i = 0; > /* no mtime change by default */ > int set_eq = 0; > long int set_time = 0; > > + struct option options[] = { > + OPT_BOOL('v', "verbose", &verbose, "print the mtime and the file name"), > + OPT_BOOL('g', "get", &get, "print only the mtime"), > + OPT_END() > + }; > > + argc = parse_options(argc, argv, NULL, options, chmtime_usage, > + PARSE_OPT_KEEP_UNKNOWN_OPT); > > + if (argc < 1 || (!get && !verbose && argc < 2)) > + usage_with_options(chmtime_usage, options); I am not sure what is going on here. The command, when parsing out the -g and -v options, expects to have and 1 or more arguments. Why should it reject argc==2 when neither -g nor -v is given, but allow argc==2 when -g and/or -v is? OK, the usage of this command is a bit opaque. The command works in two ways. * When -v/-g is given, it is a request to show the timestamp of the file, so becomes optional (i.e., when given, it sets and then shows). We still want at least one . * Otherwise, it is a request to set the timestamp, so is required, and we want at least one . Not the best way to design an end-user UI, but this is merely a test helper, so let's not complain too much ;-). > if (timespec_arg(argv[i], &set_time, &set_eq)) { > ++i; > } else { > if (get == 0 && verbose == 0) { > fprintf(stderr, "Not a base-10 integer: %s\n", argv[i] + 1); > + usage_with_options(chmtime_usage, options); > } > } This is largely the fault of the original, but I wonder if we can avoid the "without -v/-g, timespec is required" logic in two separate places like this (and the earlier one that puzzled me)? > if (i == argc) > + usage_with_options(chmtime_usage, options); And we want at least one in any case. > for (; i < argc; i++) { > struct stat sb; OK. We will iterate over the arguments given. > @@ -110,7 +110,7 @@ int cmd__chmtime(int argc, const char **argv) > > if (stat(argv[i], &sb) < 0) { > fprintf(stderr, "Failed to stat %s: %s. Skipping\n", > - argv[i], strerror(errno)); > + argv[i], strerror(errno)); > continue; > } This fixes a whitespace breakage, which is an unrelated change, but I'll let it pass. > @@ -150,14 +150,10 @@ int cmd__chmtime(int argc, const char **argv) > } > #endif > fprintf(stderr, "Failed to modify time on %s: %s\n", > - argv[i], strerror(errno)); > + argv[i], strerror(errno)); > return 1; > } > } Likewise. > > return 0; > - > -usage: > - fprintf(stderr, "usage: %s %s\n", argv[0], usage_str); > - return 1; > } We exit via usage_with_options() with 129 now, but used to exit(1) upon a command line error. Looking good. Thanks.