[07/11] linux-user: Fix layout of usage table to account for option text

Submitted by riku.voipio@linaro.org on March 11, 2013, 7:27 p.m.

Details

Message ID 63ec54d7b319824df8b60cfe25afdfb607ce3905.1363029059.git.riku.voipio@linaro.org
State New
Headers show

Commit Message

riku.voipio@linaro.org March 11, 2013, 7:27 p.m.
From: Peter Maydell <peter.maydell@linaro.org>

The linux-user usage message attempts to line up the columns in
its table by calculating the maximum width of any item in them.
However for the 'Argument' column it was only accounting for the
length of the option switch (eg "-d"), not the additional example
text (eg "item[,...]"). This currently has no adverse effects
because the widest item in the column happens to be the argumentless
"-singlestep" option, but improving the "-d" option help to read
"-d item[,...]" exceeds that limit.

Fix this by correctly calculating maxarglen as the width of the
first column text including a possible option argument, and
adjusting its uses to match.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 linux-user/main.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

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diff --git a/linux-user/main.c b/linux-user/main.c
index d8b0cd6..4e92a0b 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3406,27 +3406,35 @@  static void usage(void)
            "Options and associated environment variables:\n"
            "\n");
 
-    maxarglen = maxenvlen = 0;
+    /* Calculate column widths. We must always have at least enough space
+     * for the column header.
+     */
+    maxarglen = strlen("Argument");
+    maxenvlen = strlen("Env-variable");
 
     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
+        int arglen = strlen(arginfo->argv);
+        if (arginfo->has_arg) {
+            arglen += strlen(arginfo->example) + 1;
+        }
         if (strlen(arginfo->env) > maxenvlen) {
             maxenvlen = strlen(arginfo->env);
         }
-        if (strlen(arginfo->argv) > maxarglen) {
-            maxarglen = strlen(arginfo->argv);
+        if (arglen > maxarglen) {
+            maxarglen = arglen;
         }
     }
 
-    printf("%-*s%-*sDescription\n", maxarglen+3, "Argument",
-            maxenvlen+1, "Env-variable");
+    printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
+            maxenvlen, "Env-variable");
 
     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
         if (arginfo->has_arg) {
             printf("-%s %-*s %-*s %s\n", arginfo->argv,
-                    (int)(maxarglen-strlen(arginfo->argv)), arginfo->example,
-                    maxenvlen, arginfo->env, arginfo->help);
+                   (int)(maxarglen - strlen(arginfo->argv) - 1),
+                   arginfo->example, maxenvlen, arginfo->env, arginfo->help);
         } else {
-            printf("-%-*s %-*s %s\n", maxarglen+1, arginfo->argv,
+            printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
                     maxenvlen, arginfo->env,
                     arginfo->help);
         }