More stdout message modification

* Clear terminal (if possible) and pretty print all fields for each sample
* Clean up usage statement(s)
* mstat_find_program returns absolute path of "name" on success if "name" begins with "./"
* Zero option structure(s) at runtime

4 files changed, 83 insertions, 33 deletions

diff --git a/README.md b/README.md
index b6f011a..0fe45b5 100644
--- a/README.md
+++ b/README.md
@@ -6,12 +6,12 @@ Record the memory usage of a process over time.
 
 ```text
 usage: mstat [OPTIONS] [-p PID] | {PROGRAM... ARGS}
--c        clobber 'PID#.mstat' if it exists
--h        this help message
--o DIR    path to output directory (must exist)
--p PID    process id to monitor
--s RATE   samples per second (default: 1.00)
--v        increased verbosity
+  -c        clobber 'PID#.mstat' if it exists
+  -h        this help message
+  -o DIR    path to output directory (must exist)
+  -p PID    process id to monitor
+  -s RATE   samples per second (default: 1.00)
+  -v        increased verbosity
 ```
 
 ## Monitor an existing process
@@ -47,6 +47,15 @@ Requires `gnuplot` to be installed.
 - Arch Linux
   - `pacman -S gnuplot`
 
+```text
+usage: mstat_plot [OPTIONS] {FILE}
+  -f NAME[,...]   mstat field(s) to plot (default: rss,pss,swap)
+  -h              this help message
+  -l              list mstat fields
+  -v              verbose mode
+```
+
+### Render
 
 ```shell
 $ mstat_plot 12345.mstat
diff --git a/common.c b/common.c
index f9a8944..0fc55d5 100644
--- a/common.c
+++ b/common.c
@@ -591,11 +591,22 @@ int mstat_find_program(const char *name, char *where) {
     path = strdup(pathtmp);
     path_orig = path;
 
+    if (!strncmp(name, "./", 2)) {
+         strncpy(nametmp, realpath(name, NULL), PATH_MAX - 1);
+         if (access(nametmp, X_OK) < 0) {
+             return 1;
+         }
+         if (where) {
+             strcpy(where, nametmp);
+         }
+        return 0;
+    }
+
     char *last_element = strrchr(name, '/');
     if (last_element) {
-        strncpy(nametmp, last_element + 1, sizeof(nametmp) - 1);
+        strncat(nametmp, last_element + 1, sizeof(nametmp) - 1);
     } else {
-        strncpy(nametmp, name, sizeof(nametmp) - 1);
+        strncat(nametmp, name, sizeof(nametmp) - 1);
     }
 
     while ((token = strsep(&path, ":")) != NULL) {
diff --git a/mstat.c b/mstat.c
index 14f0651..ab66859 100644
--- a/mstat.c
+++ b/mstat.c
@@ -36,6 +36,7 @@ struct Option {
  * @param sig the trapped signal
  */
 static void handle_interrupt(int sig) {
+    printf("SIGNALED %d\n", sig);
     switch (sig) {
         case SIGCHLD:
             waitpid(option.pid, &option.status, WNOHANG|WUNTRACED);
@@ -51,7 +52,7 @@ static void handle_interrupt(int sig) {
                 fflush(option.file);
             } else {
                 if (option.verbose)
-                    fprintf(stderr, "flush request ignored. no handle");
+                    fprintf(stderr, "flush request ignored. no handle\n");
             }
             return;
         case 0:
@@ -78,12 +79,12 @@ static void usage(char *prog) {
         name = sep + 1;
     }
     printf("usage: %s [OPTIONS] [-p PID] | {PROGRAM... ARGS}\n"
-           "-c        clobber 'PID#.mstat' if it exists\n"
-           "-h        this help message\n"
-           "-o DIR    path to output directory (must exist)\n"
-           "-p PID    process id to monitor\n"
-           "-s RATE   samples per second (default: %0.2lf)\n"
-           "-v        increased verbosity\n"
+           "  -c        clobber 'PID#.mstat' if it exists\n"
+           "  -h        this help message\n"
+           "  -o DIR    path to output directory (must exist)\n"
+           "  -p PID    process id to monitor\n"
+           "  -s RATE   samples per second (default: %0.2lf)\n"
+           "  -v        increased verbosity\n"
            "", name, option.sample_rate);
 }
 
@@ -148,15 +149,26 @@ int smaps_rollup_usable(pid_t pid) {
     return access(path, F_OK | R_OK);
 }
 
+static void clearscr() {
+    printf("\33[H");
+    printf("\33[2J");
+}
 
 int main(int argc, char *argv[]) {
-    struct mstat_record_t record = {0};
-    int positional = 0;
+    struct mstat_record_t record;
+    int positional;
+
+    // Initialize options
+    memset(&option, 0, sizeof(option));
+
+    // Initialize record
+    memset(&record, 0, sizeof(record));
 
     // Set default options
     option.sample_rate = 1;
     option.verbose = 0;
     option.clobber = 0;
+
     // Set options based on arguments
     positional = parse_options(argc, argv);
     if (!option.pid && positional < 0) {
@@ -189,14 +201,14 @@ int main(int argc, char *argv[]) {
             exit(1);
         }
 
-        if (p == 0) {
-            // "where" is the path to the program to execute
-            char where[PATH_MAX] = {0};
-            if (mstat_find_program(argv[positional], where)) {
-                perror(argv[positional]);
-                exit(1);
-            }
+        // "where" is the path to the program to execute
+        char where[PATH_MAX] = {0};
+        if (mstat_find_program(argv[positional], where)) {
+            perror(argv[positional]);
+            exit(1);
+        }
 
+        if (p == 0) {
             // Execute the requested program (with arguments)
             if (execv(where, &argv[positional]) < 0) {
                 perror("execv");
@@ -262,6 +274,7 @@ int main(int argc, char *argv[]) {
 
     size_t i;
     struct timespec ts_start, ts_end;
+    extern char *mstat_field_names[];
 
     // Begin tracking time.
     clock_gettime(CLOCK_MONOTONIC, &ts_start);
@@ -271,6 +284,9 @@ int main(int argc, char *argv[]) {
            option.pid, option.sample_rate);
     i = 0;
     while (1) {
+        if (option.verbose && isatty(STDOUT_FILENO)) {
+            clearscr();
+        }
         memset(&record, 0, sizeof(record));
         record.pid = option.pid;
 
@@ -288,8 +304,19 @@ int main(int argc, char *argv[]) {
         }
 
         if (option.verbose) {
-            printf("pid: %d, sample: %zu, elapsed: %lf, rss: %li\n",
-                   record.pid, i, record.timestamp, record.rss);
+            printf("\nPID: %d, Sample: %zu, Elapsed: %lf\n----\n",
+                   record.pid, i, record.timestamp);
+            for (size_t n = 2, x = 0; mstat_field_names[n] != NULL; n++) {
+                if (x == 3) {
+                    x = 0;
+                    puts("");
+                }
+                union mstat_field_t field;
+                field = mstat_get_field_by_name(&record, mstat_field_names[n]);
+                printf("\t%-16s %-8lu ", mstat_field_names[n], field.u64);
+                x++;
+            }
+            puts("\n");
         }
 
         if (mstat_write(option.file, &record) < 0) {
diff --git a/mstat_plot.c b/mstat_plot.c
index 1357f48..3ccf888 100644
--- a/mstat_plot.c
+++ b/mstat_plot.c
@@ -166,19 +166,20 @@ static void usage(char *prog) {
     if (sep) {
         name = sep + 1;
     }
-    printf("usage: %s [OPTIONS] <FILE>\n"
-           "-h        this help message\n"
-           "-l        list mstat fields\n"
-           "-f        fields (default: rss,pss,swap)\n"
-           "-v        verbose mode\n"
-           "\n", name);
+    printf("usage: %s [OPTIONS] {FILE}\n"
+           "  -f NAME[,...]   mstat field(s) to plot (default: rss,pss,swap)\n"
+           "  -h              this help message\n"
+           "  -l              list mstat fields\n"
+           "  -v              verbose mode\n"
+           "", name);
 }
 
 void parse_options(int argc, char *argv[]) {
     if (argc < 2) {
-        fprintf(stderr, "Missing path to *.mstat data\n");
+        usage(argv[0]);
         exit(1);
     }
+
     option.fields[0] = "rss";
     option.fields[1] = "pss";
     option.fields[2] = "swap";
@@ -236,6 +237,8 @@ int main(int argc, char *argv[]) {
     size_t rec;
     FILE *fp;
 
+    // Initialize options
+    memset(&option, 0, sizeof(option));
     parse_options(argc, argv);
 
     rec = 0;