ctlstr.c

unix环境高级编程的源代码

#include    "calld.h"

/* Make a printable string of the character "c", which may be a
 * control character.  Works only with ASCII. */

char *
ctl_str(char c)
{
    static char    tempstr[6];        /* biggest is "\177" + null */

    c &= 255;
    if (c == 0)
        return("\\0");            /* really shouldn't see a null */
    else if (c < 040)
        sprintf(tempstr, "^%c", c + 'A' - 1);
    else if (c == 0177)
        return("DEL");
    else if (c > 0177)
        sprintf(tempstr, "\\%03o", c);
    else
        sprintf(tempstr, "%c", c);
    return(tempstr);
}