Remove arbitrary limits on the length of CLI prompts. Use environment

variables SQLITE_PS1 and SQLITE_PS2 (if they exist) as the default
CLI prompts.

FossilOrigin-Name: a46ceaeab968d8f376c5a225c23c0be8619fed4511b7e567baf3a8d7736c19d1

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\s\B\sescape\sfor\sprompts\sso\sthat\sit\suses\swcwidth()\sinstead\sof\nstrlen()\sto\scompute\sspacing.
-D 2026-04-11T11:24:09.462
+C Remove\sarbitrary\slimits\son\sthe\slength\sof\sCLI\sprompts.\s\sUse\senvironment\nvariables\sSQLITE_PS1\sand\sSQLITE_PS2\s(if\sthey\sexist)\sas\sthe\sdefault\nCLI\sprompts.
+D 2026-04-11T12:35:53.197
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -735,7 +735,7 @@ F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 928ff887f2a7c64275182060d94d06fdddbe32226c569781cf7e7edc6f58d7fd
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
 F src/select.c ffe199f025a0dd74670d2a77232bdea364a4d7b36f32c64a6572d39ba6a11576
-F src/shell.c.in 50505cdfdae8163b7c7476c7ad94c79c3b851274301e680dbb7b91c6d6bdc13b
+F src/shell.c.in 7ad3effc35e738c90d87b6b5336a0ddd7cc1bcb32cfc7c73cab4666e8c0afb22
 F src/sqlite.h.in a5605faa9479bbaac16c4ab43eb09ff50632004a8e05084d3fde56063ef73766
 F src/sqlite3.rc 015537e6ac1eec6c7050e17b616c2ffe6f70fca241835a84a4f0d5937383c479
 F src/sqlite3ext.h 1b7a0ee438bb5c2896d0609c537e917d8057b3340f6ad004d2de44f03e3d3cca
@@ -2197,8 +2197,8 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 7c9998de1b839cfbe12c4328ac5176f5fae981e139c5f8888b100752f5e4756b
-R effaffd5b612cee5e2c7467276ff636f
+P c6ff4f701d9cf963cf2472ed72ad4e201227560dde2ba8d48602af2e49170e89
+R 5b11b0f858f42d7a9b800b9821aa8115
 U drh
-Z 38f50b0294cde0ae9e16e79e3a672fcb
+Z c8ef1c46f1e4fc036ec422f313143d28
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-c6ff4f701d9cf963cf2472ed72ad4e201227560dde2ba8d48602af2e49170e89
+a46ceaeab968d8f376c5a225c23c0be8619fed4511b7e567baf3a8d7736c19d1

src/shell.c.in

@@ -355,11 +355,6 @@ typedef struct Mode {
 #define MFLG_CRLF  0x02  /* Use CR/LF output line endings */
 #define MFLG_HDR   0x04  /* .header used to change headers on/off */
 
-/*
-** Size of the prompt strings
-*/
-#define PROMPT_MAX 128
-
 /*
 ** State information about the database connection is contained in an
 ** instance of the following structure.
@@ -403,6 +398,7 @@ struct ShellState {
   char *zErrPrefix;      /* Alternative error message prefix */
   sqlite3_stmt *pStmt;   /* Current statement if any. */
   FILE *pLog;            /* Write log output here */
+  char *azPrompt[2];     /* Main and continuation prompt strings */
   Mode mode;             /* Current display mode */
   Mode modePrior;        /* Backup */
   struct SavedMode {     /* Ability to define custom mode configurations */
@@ -442,8 +438,6 @@ struct ShellState {
 #endif
   char zTestcase[30];           /* Name of current test case */
   char outfile[FILENAME_MAX];   /* Filename for *out */
-  char mainPrompt[PROMPT_MAX];  /* Main prompt */
-  char contPrompt[PROMPT_MAX];  /* Continuation prompt */
 };
 
 #ifdef SQLITE_SHELL_FIDDLE
@@ -793,20 +787,6 @@ static sqlite3_int64 timeOfDay(void){
 #endif
 }
 
-
-
-/* This is variant of the standard-library strncpy() routine with the
-** one change that the destination string is always zero-terminated, even
-** if there is no zero-terminator in the first n-1 characters of the source
-** string.
-*/
-static char *shell_strncpy(char *dest, const char *src, size_t n){
-  size_t i;
-  for(i=0; i<n-1 && src[i]!=0; i++) dest[i] = src[i];
-  dest[i] = 0;
-  return dest;
-}
-
 /* Indicate out-of-memory and exit. */
 static void shell_out_of_memory(void){
   eputz("Error: out of memory\n");
@@ -926,6 +906,34 @@ static char *local_getline(char *zLine, FILE *in){
   return zLine;
 }
 
+/*
+** Return the raw (unexpanded) prompt string.  This will be the
+** first of the following that exist:
+**
+**    *  The prompt string specified by the ".prompt" command.
+**    *  The value of the SQLITE_PS1 (or SQLITE_PS2) environment variable.
+**    *  The default prompt string.
+**
+** The main prompt is returned if the argument is zero and the
+** continuation prompt is returned if the argument is 1.
+*/
+static const char *prompt_string(ShellState *p, int bContinue){
+  const char *zPS;
+  assert( bContinue==0 || bContinue==1 );
+  if( p->azPrompt[bContinue] ){
+    return p->azPrompt[bContinue];
+  }
+#ifndef SQLITE_SHELL_FIDDLE
+  zPS = getenv(bContinue ? "SQLITE_PS2" : "SQLITE_PS1");
+  if( zPS ) return zPS;
+#endif
+  if( bContinue ){
+    return "\\B...\\H> ";
+  }else{
+    return "SQLite \\f> ";
+  }
+}
+
 /*
 ** Expand escapes in the given input prompt string.  Return the
 ** expanded prompt in memory obtained from sqlite3_malloc().  The
@@ -1079,7 +1087,7 @@ static char *expand_prompt(
     }
 
     if( c=='B' ){
-      /* \B is a no-op for the main prmopt.  For the continuation prompt,
+      /* \B is a no-op for the main prompt.  For the continuation prompt,
       ** \B expands to zero or more spaces to make the continuation prompt
       ** at least as wide as the main prompt. */
       if( onoff ) idxSpace = sqlite3_str_length(pOut);
@@ -1099,7 +1107,7 @@ static char *expand_prompt(
 
   /* Expand the \B, if there is one and if this is a continuation prompt */
   if( idxSpace>=0 && zPrior!=0 && zPrior[0]!=0 ){
-    char *zOther = expand_prompt(p, 0, p->mainPrompt);
+    char *zOther = expand_prompt(p, 0, prompt_string(p,0));
     size_t wOther = sqlite3_qrf_wcswidth(zOther);
     size_t wThis = sqlite3_qrf_wcswidth(sqlite3_str_value(pOut));
     sqlite3_free(zOther);
@@ -1146,7 +1154,7 @@ static char *one_input_line(
   if( in!=0 ){
     zResult = local_getline(zPrior, in);
   }else{
-    const char *zBase = bContinue ? p->contPrompt : p->mainPrompt;
+    const char *zBase = prompt_string(p, bContinue!=0);
     char *zPrompt = expand_prompt(p, zAll, zBase);
     shell_check_oom(zPrompt);
 #if SHELL_USE_LOCAL_GETLINE
@@ -10562,10 +10570,12 @@ static int do_meta_command(const char *zLine, ShellState *p){
 
   if( c=='p' && cli_strncmp(azArg[0], "prompt", n)==0 ){
     if( nArg >= 2) {
-      shell_strncpy(p->mainPrompt,azArg[1],sizeof(p->mainPrompt)-1);
+      free(p->azPrompt[0]);
+      p->azPrompt[0] = strdup(azArg[1]);
     }
     if( nArg >= 3) {
-      shell_strncpy(p->contPrompt,azArg[2],sizeof(p->contPrompt)-1);
+      free(p->azPrompt[1]);
+      p->azPrompt[1] = strdup(azArg[2]);
     }
   }else
 
@@ -12864,8 +12874,6 @@ static void main_init(ShellState *p) {
 #endif
   sqlite3_config(SQLITE_CONFIG_URI, 1);
   sqlite3_config(SQLITE_CONFIG_MULTITHREAD);
-  sqlite3_snprintf(sizeof(p->mainPrompt), p->mainPrompt,"SQLite \\f> ");
-  sqlite3_snprintf(sizeof(p->contPrompt), p->contPrompt,"\\B...\\H> ");
 }
 
 /*
@@ -13702,6 +13710,8 @@ int SQLITE_CDECL main(int argc, char **argv){
   free(data.dot.azArg);
   free(data.dot.aiOfst);
   free(data.dot.abQuot);
+  free(data.azPrompt[0]);
+  free(data.azPrompt[1]);
   if( data.nTestRun ){
     sqlite3_fprintf(stdout, "%d test%s run with %d error%s\n",
        data.nTestRun, data.nTestRun==1 ? "" : "s",
@@ -13863,6 +13873,6 @@ void fiddle_exec(const char * zSql){
 }
 
 char *fiddle_get_prompt(void){
-  return expand_prompt(&shellState, 0, &shellState.mainPrompt[0]);
+  return expand_prompt(&shellState, 0, prompt_string(&shellState,0));
 }
 #endif /* SQLITE_SHELL_FIDDLE */