diff --git a/src/util/FFstrbuf.c b/src/util/FFstrbuf.c
index 37f5cf2d3..c4a01592e 100644
--- a/src/util/FFstrbuf.c
+++ b/src/util/FFstrbuf.c
@@ -292,21 +292,22 @@ void ffStrbufTrimRightSpace(FFstrbuf* strbuf)
     strbuf->chars[strbuf->length] = '\0';
 }
 
-void ffStrbufRemoveSubstr(FFstrbuf* strbuf, uint32_t startIndex, uint32_t endIndex)
+bool ffStrbufRemoveSubstr(FFstrbuf* strbuf, uint32_t startIndex, uint32_t endIndex)
 {
     if(startIndex > strbuf->length || startIndex >= endIndex)
-        return;
+        return false;
 
     if(endIndex > strbuf->length)
     {
         ffStrbufSubstrBefore(strbuf, startIndex);
-        return;
+        return true;
     }
 
     ffStrbufEnsureFree(strbuf, 0);
     memmove(strbuf->chars + startIndex, strbuf->chars + endIndex, strbuf->length - endIndex);
     strbuf->length -= (endIndex - startIndex);
     strbuf->chars[strbuf->length] = '\0';
+    return true;
 }
 
 void ffStrbufRemoveS(FFstrbuf* strbuf, const char* str)
@@ -362,28 +363,29 @@ void ffStrbufReplaceAllC(FFstrbuf* strbuf, char find, char replace)
         *current_pos = replace;
 }
 
-void ffStrbufSubstrBefore(FFstrbuf* strbuf, uint32_t index)
+bool ffStrbufSubstrBefore(FFstrbuf* strbuf, uint32_t index)
 {
     if(strbuf->length <= index)
-        return;
+        return false;
 
     if(strbuf->allocated == 0)
     {
         //static string
         ffStrbufInitNS(strbuf, strbuf->length, strbuf->chars);
-        return;
+        return true;
     }
 
     strbuf->length = index;
     strbuf->chars[strbuf->length] = '\0';
+    return true;
 }
 
-void ffStrbufSubstrAfter(FFstrbuf* strbuf, uint32_t index)
+bool ffStrbufSubstrAfter(FFstrbuf* strbuf, uint32_t index)
 {
     if(index >= strbuf->length)
     {
         ffStrbufClear(strbuf);
-        return;
+        return true;
     }
 
     if(strbuf->allocated == 0)
@@ -391,36 +393,45 @@ void ffStrbufSubstrAfter(FFstrbuf* strbuf, uint32_t index)
         //static string
         strbuf->length -= index + 1;
         strbuf->chars += index + 1;
-        return;
+        return true;
     }
 
     memmove(strbuf->chars, strbuf->chars + index + 1, strbuf->length - index - 1);
     strbuf->length -= (index + 1);
     strbuf->chars[strbuf->length] = '\0';
+    return true;
 }
 
-void ffStrbufSubstrAfterFirstC(FFstrbuf* strbuf, char c)
+bool ffStrbufSubstrAfterFirstC(FFstrbuf* strbuf, char c)
 {
     uint32_t index = ffStrbufFirstIndexC(strbuf, c);
-    if(index < strbuf->length)
-        ffStrbufSubstrAfter(strbuf, index);
+    if(index >= strbuf->length)
+        return false;
+    ffStrbufSubstrAfter(strbuf, index);
+    return true;
 }
 
-void ffStrbufSubstrAfterFirstS(FFstrbuf* strbuf, const char* str)
+bool ffStrbufSubstrAfterFirstS(FFstrbuf* strbuf, const char* str)
 {
     if(*str == '\0')
-        return;
+        return false;
 
     uint32_t index = ffStrbufFirstIndexS(strbuf, str) + (uint32_t) strlen(str) - 1; // -1, because firstIndexS is already pointing to str[0], we want to add only the remaining length
-    if(index < strbuf->length)
-        ffStrbufSubstrAfter(strbuf, index);
+    if(index >= strbuf->length)
+        return false;
+
+    ffStrbufSubstrAfter(strbuf, index);
+    return true;
 }
 
-void ffStrbufSubstrAfterLastC(FFstrbuf* strbuf, char c)
+bool ffStrbufSubstrAfterLastC(FFstrbuf* strbuf, char c)
 {
     uint32_t index = ffStrbufLastIndexC(strbuf, c);
-    if(index < strbuf->length)
-        ffStrbufSubstrAfter(strbuf, index);
+    if(index >= strbuf->length)
+        return false;
+
+    ffStrbufSubstrAfter(strbuf, index);
+    return true;
 }
 
 uint32_t ffStrbufCountC(const FFstrbuf* strbuf, char c)
@@ -448,10 +459,13 @@ bool ffStrbufRemoveIgnCaseEndS(FFstrbuf* strbuf, const char* end)
     return false;
 }
 
-void ffStrbufEnsureEndsWithC(FFstrbuf* strbuf, char c)
+bool ffStrbufEnsureEndsWithC(FFstrbuf* strbuf, char c)
 {
-    if(!ffStrbufEndsWithC(strbuf, c))
-        ffStrbufAppendC(strbuf, c);
+    if(ffStrbufEndsWithC(strbuf, c))
+        return false;
+
+    ffStrbufAppendC(strbuf, c);
+    return true;
 }
 
 void ffStrbufWriteTo(const FFstrbuf* strbuf, FILE* file)
diff --git a/src/util/FFstrbuf.h b/src/util/FFstrbuf.h
index 92ea2da1f..a3b7179a4 100644
--- a/src/util/FFstrbuf.h
+++ b/src/util/FFstrbuf.h
@@ -56,7 +56,7 @@ void ffStrbufTrimLeft(FFstrbuf* strbuf, char c);
 void ffStrbufTrimRight(FFstrbuf* strbuf, char c);
 void ffStrbufTrimRightSpace(FFstrbuf* strbuf);
 
-void ffStrbufRemoveSubstr(FFstrbuf* strbuf, uint32_t startIndex, uint32_t endIndex);
+bool ffStrbufRemoveSubstr(FFstrbuf* strbuf, uint32_t startIndex, uint32_t endIndex);
 void ffStrbufRemoveS(FFstrbuf* strbuf, const char* str);
 void ffStrbufRemoveStrings(FFstrbuf* strbuf, uint32_t numStrings, const char* strings[]);
 
@@ -67,17 +67,18 @@ FF_C_NODISCARD uint32_t ffStrbufPreviousIndexC(const FFstrbuf* strbuf, uint32_t
 
 void ffStrbufReplaceAllC(FFstrbuf* strbuf, char find, char replace);
 
-void ffStrbufSubstrBefore(FFstrbuf* strbuf, uint32_t index);
-void ffStrbufSubstrAfter(FFstrbuf* strbuf, uint32_t index); // Not including the index
-void ffStrbufSubstrAfterFirstC(FFstrbuf* strbuf, char c);
-void ffStrbufSubstrAfterFirstS(FFstrbuf* strbuf, const char* str);
-void ffStrbufSubstrAfterLastC(FFstrbuf* strbuf, char c);
+// Returns true if the strbuf is modified
+bool ffStrbufSubstrBefore(FFstrbuf* strbuf, uint32_t index);
+bool ffStrbufSubstrAfter(FFstrbuf* strbuf, uint32_t index); // Not including the index
+bool ffStrbufSubstrAfterFirstC(FFstrbuf* strbuf, char c);
+bool ffStrbufSubstrAfterFirstS(FFstrbuf* strbuf, const char* str);
+bool ffStrbufSubstrAfterLastC(FFstrbuf* strbuf, char c);
 
 FF_C_NODISCARD uint32_t ffStrbufCountC(const FFstrbuf* strbuf, char c);
 
 bool ffStrbufRemoveIgnCaseEndS(FFstrbuf* strbuf, const char* end);
 
-void ffStrbufEnsureEndsWithC(FFstrbuf* strbuf, char c);
+bool ffStrbufEnsureEndsWithC(FFstrbuf* strbuf, char c);
 
 void ffStrbufWriteTo(const FFstrbuf* strbuf, FILE* file);
 void ffStrbufPutTo(const FFstrbuf* strbuf, FILE* file);
@@ -383,14 +384,14 @@ static inline FF_C_NODISCARD uint32_t ffStrbufLastIndexC(const FFstrbuf* strbuf,
     return ffStrbufPreviousIndexC(strbuf, strbuf->length - 1, c);
 }
 
-static inline void ffStrbufSubstrBeforeFirstC(FFstrbuf* strbuf, char c)
+static inline bool ffStrbufSubstrBeforeFirstC(FFstrbuf* strbuf, char c)
 {
-    ffStrbufSubstrBefore(strbuf, ffStrbufFirstIndexC(strbuf, c));
+    return ffStrbufSubstrBefore(strbuf, ffStrbufFirstIndexC(strbuf, c));
 }
 
-static inline void ffStrbufSubstrBeforeLastC(FFstrbuf* strbuf, char c)
+static inline bool ffStrbufSubstrBeforeLastC(FFstrbuf* strbuf, char c)
 {
-    ffStrbufSubstrBefore(strbuf, ffStrbufLastIndexC(strbuf, c));
+    return ffStrbufSubstrBefore(strbuf, ffStrbufLastIndexC(strbuf, c));
 }
 
 static inline FF_C_NODISCARD bool ffStrbufStartsWithC(const FFstrbuf* strbuf, char c)
diff --git a/tests/strbuf.c b/tests/strbuf.c
index 0a35012d2..01db4e094 100644
--- a/tests/strbuf.c
+++ b/tests/strbuf.c
@@ -93,12 +93,26 @@ int main(void)
 
     //substr
 
-    ffStrbufSubstrBefore(&strbuf, 9);
+    VERIFY(ffStrbufSubstrBefore(&strbuf, 9));
     VERIFY(strbuf.length == 9);
     VERIFY(strbuf.allocated >= 110);
     VERIFY(strbuf.chars[strbuf.length] == 0);
     VERIFY(ffStrbufEqualS(&strbuf, "123456789"));
 
+    VERIFY(!ffStrbufSubstrBeforeFirstC(&strbuf, '0'));
+    VERIFY(!ffStrbufSubstrBeforeLastC(&strbuf, '0'));
+    VERIFY(!ffStrbufSubstrAfterFirstC(&strbuf, '0'));
+    VERIFY(!ffStrbufSubstrAfterLastC(&strbuf, '0'));
+    VERIFY(ffStrbufEqualS(&strbuf, "123456789"));
+
+    VERIFY(ffStrbufSubstrBeforeFirstC(&strbuf, '9'));
+    VERIFY(ffStrbufSubstrBeforeLastC(&strbuf, '8'));
+    VERIFY(ffStrbufSubstrAfterFirstC(&strbuf, '1'));
+    VERIFY(ffStrbufSubstrAfterLastC(&strbuf, '2'));
+    VERIFY(ffStrbufEqualS(&strbuf, "34567"));
+
+    ffStrbufSetS(&strbuf, "123456789");
+
     //startsWithC
 
     VERIFY(ffStrbufStartsWithC(&strbuf, '1'));
@@ -313,7 +327,7 @@ int main(void)
 
     //ffStrbufCreateStatic / Substr
     ffStrbufInitStatic(&strbuf, "__TEST__");
-    ffStrbufRemoveSubstr(&strbuf, 0, 6);
+    VERIFY(ffStrbufRemoveSubstr(&strbuf, 0, 6));
     VERIFY(ffStrbufEqualS(&strbuf, "__"));
     VERIFY(strbuf.length == 2);
     VERIFY(strbuf.allocated > 0);
@@ -321,7 +335,7 @@ int main(void)
 
     //ffStrbufCreateStatic / Substr
     ffStrbufInitStatic(&strbuf, "__TEST__");
-    ffStrbufRemoveSubstr(&strbuf, 2, 8);
+    VERIFY(ffStrbufRemoveSubstr(&strbuf, 2, 8));
     VERIFY(ffStrbufEqualS(&strbuf, "__"));
     VERIFY(strbuf.length == 2);
     VERIFY(strbuf.allocated > 0);
@@ -329,13 +343,13 @@ int main(void)
 
     //ffStrbufCreateStatic / Substr
     ffStrbufInitStatic(&strbuf, "__TEST__");
-    ffStrbufRemoveSubstr(&strbuf, 2, 6);
+    VERIFY(ffStrbufRemoveSubstr(&strbuf, 2, 6));
     VERIFY(ffStrbufEqualS(&strbuf, "____"));
     VERIFY(strbuf.length == 4);
     VERIFY(strbuf.allocated > 0);
     ffStrbufDestroy(&strbuf);
 
-    //ffStrbufCreateStatic / Substr
+    //ffStrbufCreateStatic / ReplaceAllC
     ffStrbufInitStatic(&strbuf, "__TEST__");
     ffStrbufReplaceAllC(&strbuf, '_', '-');
     VERIFY(ffStrbufEqualS(&strbuf, "--TEST--"));
@@ -403,5 +417,5 @@ int main(void)
     ffStrbufDestroy(&strbuf);
 
     //Success
-    puts("\033[32mAll tests passed!" FASTFETCH_TEXT_MODIFIER_RESET);
+    puts("\e[32mAll tests passed!" FASTFETCH_TEXT_MODIFIER_RESET);
 }