写了一个去除空格的函数^_^.

直接贴源码吧，主要是备查。

file: trim.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#ifndef SUCCESS
#define SUCCESS     1
#endif

/* TRIM LEFT */

int rtrim( char *pszString)
{
    int nForwardCursor = 0;
    int nTrailingCursor = 0;
    int bTrim = 1;

    for( nForwardCursor = 0 ; pszString[nForwardCursor] != '\0'; nForwardCursor++ )
        if ( bTrim && isspace( pszString[nForwardCursor] ))
            continue ;
        else {
            bTrim = 0;
            pszString[nTrailingCursor] = pszString[nForwardCursor];
            nTrailingCursor++;
        }
    pszString[nTrailingCursor] = '\0';
    return SUCCESS;
}

/* TRIM RIGHT */
int ltrim( char *pszString )
{
    int nForwardCursor = 0;
    int nTrailingCursor = 0;
    int bTrim = 1;
    for ( nForwardCursor=strlen(pszString)-1;
            nForwardCursor >= 0 && isspace( pszString[nForwardCursor] );
            nForwardCursor-- )
    {
    }
    pszString[nForwardCursor+1] = '\0';
    return SUCCESS;
}

/* TRIM LEFT & RIGHT */
int trim(char *str)
{
    ltrim(str);
    rtrim(str);
    return SUCCESS;
}

测试代码如下：
file: test.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int main( void )
{
    char    s[80];
    sprintf(s,"%s","     aaaaaa      ");
    printf("=== strlen = %d === \n",strlen(s));
    trim(s);
    printf("=== len = %d ===\n",strlen(s));
    return 0;
}

编译：
cc -o test test.c trim.c

运行：
$ ./test