diff options
| -rw-r--r-- | servicecmd/disable.c | 7 | ||||
| -rw-r--r-- | servicecmd/enable.c | 7 | ||||
| -rw-r--r-- | servicecmd/servicecmd.c | 17 | ||||
| -rw-r--r-- | servicecmd/servicecmd.h | 15 |
4 files changed, 36 insertions, 10 deletions
diff --git a/servicecmd/disable.c b/servicecmd/disable.c index 1901381..8a6f9f3 100644 --- a/servicecmd/disable.c +++ b/servicecmd/disable.c @@ -31,18 +31,15 @@ static int cmd_disable(int argc, char **argv) char *linkname, *ptr; struct stat sb; - if (argc < 2 || argc > 3) { - fputs("Wrong number of arguments for `disable'.\n" - "Try `service help disable' for more information.\n", - stderr); + if (check_arguments(argv[0], argc, 2, 3)) return EXIT_FAILURE; - } for (ptr = argv[1]; isalnum(*ptr) || *ptr == '_'; ++ptr) ; if (*ptr != '\0') { fprintf(stderr, "Invalid service name '%s'\n", argv[1]); + tell_read_help(argv[0]); return EXIT_FAILURE; } diff --git a/servicecmd/enable.c b/servicecmd/enable.c index 73ea01e..5d4195e 100644 --- a/servicecmd/enable.c +++ b/servicecmd/enable.c @@ -31,18 +31,15 @@ static int cmd_enable(int argc, char **argv) int ret = EXIT_FAILURE; struct stat sb; - if (argc < 2 || argc > 3) { - fputs("Wrong number of arguments for `enable'.\n" - "Try `service help enable' for more information.\n", - stderr); + if (check_arguments(argv[0], argc, 2, 3)) return EXIT_FAILURE; - } for (ptr = argv[1]; isalnum(*ptr) || *ptr == '_'; ++ptr) ; if (*ptr != '\0') { fprintf(stderr, "Invalid service name '%s'\n", argv[1]); + tell_read_help(argv[0]); return EXIT_FAILURE; } diff --git a/servicecmd/servicecmd.c b/servicecmd/servicecmd.c index ff37740..84e6a32 100644 --- a/servicecmd/servicecmd.c +++ b/servicecmd/servicecmd.c @@ -55,6 +55,23 @@ void usage(int status) exit(status); } +void tell_read_help(const char *cmd) +{ + fprintf(stderr, "Try `%s help %s' for more information.\n", + __progname, cmd); +} + +int check_arguments(const char *cmd, int argc, int minc, int maxc) +{ + if (argc >= minc && argc <= maxc) + return 0; + + fprintf(stderr, "Too %s arguments for `%s'\n", + argc > maxc ? "many" : "few", cmd); + tell_read_help(cmd); + return -1; +} + int main(int argc, char **argv) { command_t *cmd; diff --git a/servicecmd/servicecmd.h b/servicecmd/servicecmd.h index 27204d0..b839799 100644 --- a/servicecmd/servicecmd.h +++ b/servicecmd/servicecmd.h @@ -61,6 +61,21 @@ extern command_t *commands; void usage(int status) NORETURN; /* + Write a message to stderr that advises the user how to consult the + help text for a specific command. +*/ +void tell_read_help(const char *cmd); + +/* + Check if the argument count is within specified bounds (minc and maxc + inclusive). If it is, return 0. + + If it isn't, complain about a wrong number of arguments for a + command (cmd), tell the user to consult the help text and return -1. +*/ +int check_arguments(const char *cmd, int argc, int minc, int maxc); + +/* To implement a new command, add a global, static instance of a command_t (or derived) structure to a C file and pass it to this macro to have it automatically registered on program startup. |