diff options
| -rw-r--r-- | include/version.h | 2 | ||||
| -rw-r--r-- | man/1/m4 | 27 |
2 files changed, 22 insertions, 7 deletions
diff --git a/include/version.h b/include/version.h index b7724707..94c30352 100644 --- a/include/version.h +++ b/include/version.h @@ -1 +1 @@ -#define VERSION "Fourth Edition (20090320)" +#define VERSION "Fourth Edition (20090418)" @@ -31,9 +31,20 @@ A comma within a nested parenthesis is part of an argument value, not an argumen Potential macro names consist of alphabetic letters, Unicode characters, digits, and underscore `\_', where the first character is not a digit. .PP -The left and right single quotes(ie, grave and acute accents \`\|\' ) are used to quote strings. +Comments begin with the +.B # +character and extend to the end of that line; the characters in a comment are copied to the current +output stream unchanged. +The comment start and end sequences may be changed using the +.B changecom +call described below. +.PP +The left and right single quotes (ie, grave and acute accents \`\|\' ) are used to quote strings. Because the left and right quotes are distinct, quoted strings may nest. The value of a quoted string is the string stripped of the outermost quotes. +The left and right quote characters may be changed using the +.B changequote +call described below. .PP When .I m4 @@ -80,9 +91,10 @@ is replaced by the argument of that macro call. Argument 0 is the name of the macro; missing arguments are replaced by the null string. -If the macro value is the same as its name, or the value is simply +If the macro value is the same as its name, or the value is .BR $0 , the result is the macro name. +To prevent expansion of a name when redefining a macro, quote the first argument. .TP divert .I M4 @@ -113,7 +125,9 @@ Prints its argument on the diagnostic output file. .TP eval -Evaluates its argument as an arithmetic expression, using 32-bit arithmetic. +Evaluates its argument as an arithmetic expression, using 32-bit arithmetic, +and returns the result as a signed decimal integer. +The only literals are decimal integers. Operators are those of Limbo: the binary operators .BR || , .BR && , @@ -133,7 +147,7 @@ the unary operators .BR ~ , .BR ! ; and parenthesis. -The operator precedence is the same as in Limbo. +Operator precedence is the same as in Limbo. Right shifts are signed. .TP ifdef @@ -226,8 +240,9 @@ the given macro which may be one of the predefined macros. .PP .I M4 -in Inferno is more closely related to the original version in Seventh Edition UNIX -than the more elaborate relatives in System V and POSIX. +in Inferno is more closely related to the original +.I m4 +in Seventh Edition UNIX than its more elaborate relatives in System V and POSIX. .SH "SEE ALSO" B. W. Kernighan and D. M. Ritchie, .I The M4 Macro Processor |