Move "get max pid" code into platform specific area.

Process.c

@@ -11,6 +11,7 @@ in the source distribution for its full text.
 #include "CRT.h"
 #include "String.h"
 #include "RichString.h"
+#include "Platform.h"
 
 #include <stdio.h>
 #include <sys/time.h>
@@ -284,12 +285,9 @@ static int Process_getuid = -1;
 static char* Process_pidFormat = "%7u ";
 static char* Process_tpgidFormat = "%7u ";
 
-void Process_getMaxPid() {
-   FILE* file = fopen(PROCDIR "/sys/kernel/pid_max", "r");
-   if (!file) return;
-   int maxPid = 4194303;
-   fscanf(file, "%32d", &maxPid);
-   fclose(file);
+void Process_setupColumnWidths() {
+   int maxPid = Platform_getMaxPid();
+   if (maxPid == -1) return;
    if (maxPid > 99999) {
       Process_fieldTitles[PID] =     "    PID ";
       Process_fieldTitles[PPID] =    "   PPID ";

Process.h

@@ -179,7 +179,7 @@ extern const int Process_fieldFlags[];
 extern const char *Process_fieldTitles[];
 
 
-void Process_getMaxPid();
+void Process_setupColumnWidths();
 
 #define ONE_K 1024L
 #define ONE_M (ONE_K * ONE_K)

htop.c

@@ -680,7 +680,7 @@ int main(int argc, char** argv) {
    ProcessList* pl = ProcessList_new(ut, pidWhiteList);
    pl->userOnly = userOnly;
    pl->userId = userId;
-   Process_getMaxPid();
+   Process_setupColumnWidths();
    
    Header* header = Header_new(pl);
    Settings* settings = Settings_new(pl, header, pl->cpuCount);

linux/Platform.c

@@ -93,3 +93,12 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    }
 }
 
+int Platform_getMaxPid() {
+   FILE* file = fopen(PROCDIR "/sys/kernel/pid_max", "r");
+   if (!file) return -1;
+   int maxPid = 4194303;
+   fscanf(file, "%32d", &maxPid);
+   fclose(file);
+   return maxPid;
+}
+

unsupported/Platform.c

@@ -54,3 +54,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *five = 0;
    *fifteen = 0;
 }
+
+int Platform_getMaxPid() {
+   return -1;
+}