printf: postion cursor to output columns

schneidz · 09-19-2005, 08:02 PM

hi lq, this works how i want in redhat linux (the first example). but in aix it doesn't work. see below for code/output

Code:

[schneidz@lq file-lst]$ cat columnate.c
#include <stdio.h>
#include <string.h>
 

int main(int argc, char *argv[])
{
 FILE * fstream;
 fstream = fopen(argv[1], "r");
 char buff[255], col1[64], col2[64], col3[64];
 int y = 3;
 int x = 5;
 int c;
 

 c = fscanf(fstream, "%s", &col1);
/*/ while(fgets(buff, 255, fstream) != EOF) /*/
 while(c == 1)
 {
  printf("\e[%d;%d%c%s\n", y, x, 'H', col1);
  x += 20;
  c = fscanf(fstream, "%s", &col2);
  printf("\e[%d;%d%c%s\n", y, x, 'H', col2);
  x += 20;
  c = fscanf(fstream, "%s", &col3);
  printf("\e[%d;%d%c%s\n", y, x, 'H', col3);
  y++;
  x = 5;
  c = fscanf(fstream, "%s", &col1);
 }
 return 0;
}
[schneidz@lq file-lst]$ cat test.txt
row1 l33t h4x0r
row2 hello world
row3 chun-li akuma
[schneidz@lq file-lst]$ columnate.x shh.txt
                                                                                
    row1                l33t                h4x0r
    row2                hello               world
    row3                chun-li             akuma

this is what it does in aix:

Code:

/datasheets> cc  columnate.c -o columnate.x
"columnate.c", line 14.46: 1506-342 (W) "/*" detected in comment.
"columnate.c", line 17.10: 1506-235 (W) Incorrect escape sequence \e. \
ignored.
"columnate.c", line 20.10: 1506-235 (W) Incorrect escape sequence \e. \
ignored.
"columnate.c", line 23.10: 1506-235 (W) Incorrect escape sequence \e. \
ignored.

/datasheets>  columnate.x test.lst
e[3;5Hrow1
e[3;25Hl33t
e[3;45Hh4x0r
e[4;5Hrow2
e[4;25Hhello
e[4;45Hworld
e[5;5Hrow3
e[5;25Hchun-li
e[5;45Hakuma

can someone help me figure out how to handle this escape sequence in aix...
thanks,

Matir · 09-19-2005, 08:28 PM

My guess would be that the AIX c libraries and terminals don't support the use of those escape sequences to position the cursor. They may not support any such escape sequences. You may want to look at ncurses.

Wim Sturkenboom · 09-19-2005, 11:47 PM

Creating colums using printf is easy:

Code:

printf("%-20s %10d\n",text1,int1);

will create a 20 char textfield (left aligned) and a 10 char number field. Replace -20s by 20s if you want it right-aligned text field.

This should work on all platforms.

Please note that if the string is greater than the allocated space, your columns get corrupted.

paulsm4 · 09-20-2005, 01:25 AM

There are several separate issues here:
1. Q: Why doesn't the AIX C compiler recognize "\e"?
A: Because it doesn't - and it doesn't have to. "\e" is an extension.

2. Q: Even if the AIX C compiler recognized the "esc", would the
AIX runtime correctly format my columns?
A: Not necessarily. It would *only* work if your terminal driver
happened to recognize and handle ANSI escape sequences.

In answer to Q1: All you have to do is specify the escape in binary (ascii(27)), instead of using "\e":

"e[3;5H" == "\0x1b[3;5H"

In answer to Q2, the best way to assure consistent formatting (without having to worry about whether or not your user's display supports ANSI escape sequences) is to use the built-in formatting provided by "printf", as Wim suggested.

You can also, as Matir point out, use "curses", which is a layer *abve* ANSI escapes (and, in fact, ANSI escapes are one of many terminal control protocols supported by curses).

Your .. PSM

schneidz · 09-20-2005, 08:55 AM

thanks, i'll try them out.

good discussion paul/ matir

i needed that example wim. i didn't know how to do column formatting in printf (definately one of those things that are easy, if you know how to do it )

happy hacking,

Wim Sturkenboom · 09-20-2005, 08:59 AM

Quote:

Originally posted by schneidz
i needed that example wim. i didn't know how to do column formatting in printf (definately one of those things that are easy, if you know how to do it )

Took me a long time as well.