ustd: allow to choose the trace location and add command line option system

diff --git a/ustd/ustd.c b/ustd/ustd.c
index a70f2f70a209f3436864ed50efac25275ab20000..470401649cdb8c55099a07e98a2946e80653a6ab 100644 (file)
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -18,6 +18,7 @@
 #define _GNU_SOURCE
 
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <sys/shm.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -29,6 +30,7 @@
 #include <string.h>
 #include <errno.h>
 #include <assert.h>
+#include <getopt.h>
 
 #include "ustd.h"
 #include "localerr.h"
@@ -48,7 +50,8 @@
 #define PUT_SUBBUF_PUSHED 2
 
 char *sock_path=NULL;
- 
+char *trace_path=NULL;
+
 int test_sigpipe(void)
 {
        sigset_t sigset;
@@ -261,6 +264,24 @@ int create_dir_if_needed(char *dir)
        return 0;
 }
 
+int is_directory(const char *dir)
+{
+       int result;
+       struct stat st;
+
+       result = stat(dir, &st);
+       if(result == -1) {
+               PERROR("stat");
+               return 0;
+       }
+
+       if(!S_ISDIR(st.st_mode)) {
+               return 0;
+       }
+
+       return 1;
+}
+
 int add_buffer(pid_t pid, char *bufname)
 {
        struct buffer_info *buf;
@@ -359,13 +380,21 @@ int add_buffer(pid_t pid, char *bufname)
        buf->memlen = shmds.shm_segsz;
 
        /* open file for output */
-       result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
-       if(result == -1) {
-               ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
-               return -1;
+       if(!trace_path) {
+               /* Only create the directory if using the default path, because
+                * of the risk of typo when using trace path override. We don't
+                * want to risk creating plenty of useless directories in that case.
+                */
+               result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
+               if(result == -1) {
+                       ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
+                       return -1;
+               }
+
+               trace_path = USTD_DEFAULT_TRACE_PATH;
        }
 
-       asprintf(&tmp, "%s/%u", USTD_DEFAULT_TRACE_PATH, buf->pid);
+       asprintf(&tmp, "%s/%u", trace_path, buf->pid);
        result = create_dir_if_needed(tmp);
        if(result == -1) {
                ERR("could not create directory %s", tmp);
@@ -374,7 +403,7 @@ int add_buffer(pid_t pid, char *bufname)
        }
        free(tmp);
 
-       asprintf(&tmp, "%s/%u/%s_0", USTD_DEFAULT_TRACE_PATH, buf->pid, buf->name);
+       asprintf(&tmp, "%s/%u/%s_0", trace_path, buf->pid, buf->name);
        result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 00600);
        if(result == -1) {
                PERROR("open");
@@ -389,13 +418,76 @@ int add_buffer(pid_t pid, char *bufname)
        return 0;
 }
 
+void usage(void)
+{
+       fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
+                       "\t-h\t\tDisplay this usage.\n"
+                       "\t-o DIR\t\tSpecify the directory where to output the traces.\n"
+                       "\t-s PATH\t\tSpecify the path to use for the daemon socket.\n");
+}
+
+int parse_args(int argc, char **argv)
+{
+       int c;
+
+       while (1) {
+               int option_index = 0;
+               static struct option long_options[] = {
+                       {"help", 0, 0, 'h'},
+                       {"version", 0, 0, 'V'},
+                       {0, 0, 0, 0}
+               };
+
+               c = getopt_long(argc, argv, "hs:o:", long_options, &option_index);
+               if (c == -1)
+                       break;
+
+               switch (c) {
+               case 0:
+                       printf("option %s", long_options[option_index].name);
+                       if (optarg)
+                               printf(" with arg %s", optarg);
+                       printf("\n");
+                       break;
+               case 's':
+                       sock_path = optarg;
+                       break;
+               case 'o':
+                       trace_path = optarg;
+                       if(!is_directory(trace_path)) {
+                               ERR("Not a valid directory. (%s)", trace_path);
+                               return -1;
+                       }
+                       break;
+               case 'h':
+                       usage();
+                       exit(0);
+               case 'V':
+                       printf("Version 0.0\n");
+                       break;
+
+               default:
+                       /* unknown option or other error; error is
+                       printed by getopt, just return */
+                       return -1;
+               }
+       }
+
+       return 0;
+}
+
 int main(int argc, char **argv)
 {
        struct ustcomm_ustd ustd;
        int result;
        sigset_t sigset;
 
-       result = ustcomm_init_ustd(&ustd);
+       result = parse_args(argc, argv);
+       if(result == -1) {
+               exit(1);
+       }
+
+       result = ustcomm_init_ustd(&ustd, sock_path);
        if(result == -1) {
                ERR("failed to initialize socket");
                return 1;