串聯空白與C/C++

我是新來編程，我想從一個表中，我們已經嘗試過的線路之一提取數據：串聯空白與C/C++

const int buf_length = 255; 
char buf[buf_length+1]; 
int i, count, cur = 0; 
................................................................... 
snprintf(buf, buf_length, "%s %s", first_child, get_name(table)); 
name_list(list, cur++, buf, 1);

這是結果：

01-10 Aaron 
02-20 Christian 
03-30 Dean

我想在行的beginnig處插入5個空格。

因爲「name_list_text」，從刪除緩衝器中的前導空白：

int name_list_text(list_t *list, int cur, const char *textarg, 
         int numlines, int maxwidth) 
{ 
static const char ellipsis[] = "..."; 
const size_t ellipsislen = strlen(ellipsis); 
int textlen; 
int lastline = cur + numlines; 
char textbuf[4096]; 
char *text = textbuf; 
int width; 
int breakpos; 
int maxwidthpos; 
int pos; 

/* 
* Make a copy of the textarg, since we'll want to be able to do 
* changes to our local copy. 
*/ 
snprintf(text, 4096, "%s", textarg); 

while(cur <= lastline) { 
    /* Eat leading whitespace */ 
    while(isspace(*text)) 
     text++, textarg++; 

    textlen = strlen(text); 
    if(textlen == 0) 
     break; 

    /* 
    * Seek to the end of the line. This has to been done iteratively, 
    * since we have to decode the UTF-8 to skip over any tail bytes. 
    */ 
    pos = 0; 
    width = 0; 
    while(width < maxwidth) { 
     width++; 
     /* Skip tail bytes */ 
     while((text[ ++pos ] & 0xc0) == 0x80) 
      ; 
     if(text[pos] == '\0') { 
      breakpos = pos; 
      goto breaknow; 
     } 
    } 
    maxwidthpos = pos; 

    breakpos = -1; 
    for(pos = 0; pos <= maxwidthpos; pos++) { 
     if(isspace(text[ pos ]) || text[ pos ] == '\0') { 
      breakpos = pos; 
      if(text[ pos ] == '\n') 
       break; 
     } 
    } 
    if(breakpos == -1) { 
     /* This place is as good as any to break... */ 
     breakpos = maxwidthpos; 
    } 

    if(cur == lastline) { 
     if(breakpos < textlen) { 
      /* Seek back to fit the ellipsis. */ 
      pos = breakpos; 
      pos -= ellipsislen; 
      /* Make sure to land at the start of a UTF-8 character. */ 
      while((text[ pos ] & 0xc0) == 0x80) 
       pos--; 
      /* Write the ellipsis. Bounds have been checked. */ 
      strcpy (text+pos, ellipsis); 
     } 
    } 
breaknow: 
    text[ breakpos ] = '\0'; 
    list_set_text(list, cur++, text); 
    text[ breakpos ] = textarg[ breakpos ]; 
    text = &text[ breakpos ]; 
    textarg = &textarg[ breakpos ]; 
    } 
return cur; 
}

不能使用

"\t%s %s"

或

"  %s %s" 
    ^^^^^

在功能

。

期望的結果：

 01-10 Aaron 
    02-20 Christian 
    03-30 Dean 
^^^^^

在緩衝器如何可以連接（whitout變化「name_list_text」）：

「5空白」 +「的snprintf（BUF，buf_length，「％S％S」， first_child，get_name（table））;「

posibile解決方案是使用「隱形字符」像ASCII空格：

snprintf(buf, buf_length, "\32  %s %s", first_child, get_name(table)); 
name_list(list, cur++, buf, 1);

感謝。

來源

2012-01-14 user934718

這是一個有點混亂，你的問題實際上是什麼了。你能展示更多的代碼和評論你的每個函數在做什麼？ – Pubby 2012-01-14 16:10:30

將空格添加到格式字符串？

snprintf(buf, buf_length, "  %s %s", first_child, get_name(table)); 
          ^^^^^

buf_length + 5可能需要的緩衝區的大小的參數。

如果你的函數刪除空格，兩件事情可以做：

1）改變功能。

2）print(" ");調用該函數

來源

2012-01-14 16:02:29 Pubby

串聯空白與C/C++

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