sendmail, 4th Edition

SCANF

Support scanf(3) with the F command Tune with confENVDEF

The F configuration command (The F Class Command on page 857) allows the specification of a scanf(3)-style string to aid in parsing files (scanf(3) variations on page 858). This ability is enabled at compile time by default. If you don’t need it, you can exclude its support with the following line in your Build m4 file:

APPENDDEF(`confENVDEF', `-DSCANF=0')
                                 ↑
                           disable scanf(3)

The scanf(3) function is used only in reading files into a class with the F configuration command.

If you are running a precompiled sendmail binary, you can use the -d0.1 debugging command-line switch (-d0.1 on page 542) to determine whether SCANF support is included (if it appears in the list, support is included).