Dynamically adjust the size of line reads

* Dynamically adjust the size of line reads.
* Remove some more uses of fgets with arbitrary sizes.
* Fix reading of lines and width of n column.

Fixes #514.

5 files changed, 58 insertions, 25 deletions

diff --git a/OpenFilesScreen.c b/OpenFilesScreen.c
index 1eda3731..80079d04 100644
--- a/OpenFilesScreen.c
+++ b/OpenFilesScreen.c
@@ -86,17 +86,12 @@ static OpenFiles_ProcessData* OpenFilesScreen_getProcessData(pid_t pid) {
       pdata->error = 127;
       return pdata;
    }
-   while (!feof(fd)) {
-      int cmd = fgetc(fd);
-      if (cmd == EOF)
-         break;
-      char* entry = xMalloc(1024);
-      if (!fgets(entry, 1024, fd)) {
-         free(entry);
+   for (;;) {
+      char* line = String_readLine(fd);
+      if (!line) {
          break;
       }
-      char* newline = strrchr(entry, '\n');
-      *newline = '\0';
+      unsigned char cmd = line[0];
       if (cmd == 'f') {
          OpenFiles_FileData* nextFile = xCalloc(1, sizeof(OpenFiles_FileData));
          if (fdata == NULL) {
@@ -108,7 +103,8 @@ static OpenFiles_ProcessData* OpenFilesScreen_getProcessData(pid_t pid) {
          item = &(fdata->data);
       }
       assert(cmd >= 0 && cmd <= 0xff);
-      item->data[cmd] = entry;
+      item->data[cmd] = xStrdup(line + 1);
+      free(line);
    }
    pdata->error = pclose(fd);
    return pdata;
@@ -132,9 +128,11 @@ void OpenFilesScreen_scan(InfoScreen* this) {
    } else {
       OpenFiles_FileData* fdata = pdata->files;
       while (fdata) {
-         char entry[1024];
          char** data = fdata->data.data;
-         sprintf(entry, "%5s %4s %10s %10s %10s %s",
+         int lenN = data['n'] ? strlen(data['n']) : 0;
+         int sizeEntry = 5 + 7 + 10 + 10 + 10 + lenN + 5 /*spaces*/ + 1 /*null*/;
+         char* entry = xMalloc(sizeEntry);
+         snprintf(entry, sizeEntry, "%5.5s %7.7s %10.10s %10.10s %10.10s %s",
             data['f'] ? data['f'] : "",
             data['t'] ? data['t'] : "",
             data['D'] ? data['D'] : "",
diff --git a/Settings.c b/Settings.c
index eaca7829..0e296c10 100644
--- a/Settings.c
+++ b/Settings.c
@@ -173,12 +173,15 @@ static bool Settings_read(Settings* this, const char* fileName) {
    if (!fd)
       return false;
    
-   const int maxLine = 2048;
-   char buffer[maxLine];
    bool readMeters = false;
-   while (fgets(buffer, maxLine, fd)) {
+   for (;;) {
+      char* line = String_readLine(fd);
+      if (!line) {
+         break;
+      }
       int nOptions;
-      char** option = String_split(buffer, '=', &nOptions);
+      char** option = String_split(line, '=', &nOptions);
+      free (line);
       if (nOptions < 2) {
          String_freeArray(option);
          continue;
diff --git a/StringUtils.c b/StringUtils.c
index 4465fb15..b53f5eea 100644
--- a/StringUtils.c
+++ b/StringUtils.c
@@ -13,9 +13,10 @@ in the source distribution for its full text.
 #include <string.h>
 #include <strings.h>
 #include <stdlib.h>
-#include <stdio.h>
 
 /*{
+#include <stdio.h>
+
 #define String_startsWith(s, match) (strstr((s), (match)) == (s))
 #define String_contains_i(s1, s2) (strcasestr(s1, s2) != NULL)
 }*/
@@ -119,3 +120,29 @@ char* String_getToken(const char* line, const unsigned short int numMatch) {
    match[foundCount] = '\0';
    return((char*)xStrdup(match));
 }
+
+char* String_readLine(FILE* fd) {
+   const int step = 1024;
+   int bufSize = step;
+   char* buffer = xMalloc(step + 1);
+   char* at = buffer;
+   for (;;) {
+      char* ok = fgets(at, step + 1, fd);
+      if (!ok) {
+         free(buffer);
+         return NULL;
+      }
+      char* newLine = strrchr(at, '\n');
+      if (newLine) {
+         *newLine = '\0';
+         return buffer;
+      } else {
+         if (feof(fd)) {
+            return buffer;
+         }
+      }
+      bufSize += step;
+      buffer = xRealloc(buffer, bufSize + 1);
+      at = buffer + bufSize - step;
+   }
+}
diff --git a/StringUtils.h b/StringUtils.h
index 38ffae7f..97620342 100644
--- a/StringUtils.h
+++ b/StringUtils.h
@@ -9,6 +9,8 @@ Released under the GNU GPL, see the COPYING file
 in the source distribution for its full text.
 */
 
+#include <stdio.h>
+
 #define String_startsWith(s, match) (strstr((s), (match)) == (s))
 #define String_contains_i(s1, s2) (strcasestr(s1, s2) != NULL)
 
@@ -24,4 +26,6 @@ void String_freeArray(char** s);
 
 char* String_getToken(const char* line, const unsigned short int numMatch);
 
+char* String_readLine(FILE* fd);
+
 #endif
diff --git a/linux/Battery.c b/linux/Battery.c
index 572bad48..10681844 100644
--- a/linux/Battery.c
+++ b/linux/Battery.c
@@ -65,10 +65,11 @@ static unsigned long int parseBatInfo(const char *fileName, const unsigned short
          break;
       }
 
-      char line[50] = "";
+      char* line = NULL;
       for (unsigned short int i = 0; i < lineNum; i++) {
-         char* ok = fgets(line, sizeof line, file);
-         if (!ok) break;
+         free(line);
+         line = String_readLine(file);
+         if (!line) break;
       }
 
       fclose(file);
@@ -76,7 +77,8 @@ static unsigned long int parseBatInfo(const char *fileName, const unsigned short
       char *foundNumStr = String_getToken(line, wordNum);
       const unsigned long int foundNum = atoi(foundNumStr);
       free(foundNumStr);
-
+      free(line);
+      
       total += foundNum;
    }
 
@@ -116,14 +118,13 @@ static ACPresence procAcpiCheck() {
          continue;
       }
 
-      char line[100];
-      char* ok = fgets(line, sizeof line, file);
-      if (!ok) continue;
-      line[sizeof(line) - 1] = '\0';
+      char* line = String_readLine(file);
+      if (!line) continue;
 
       fclose(file);
 
       const char *isOnline = String_getToken(line, 2);
+      free(line);
 
       if (strcmp(isOnline, "on-line") == 0) {
          isOn = AC_PRESENT;