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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/doc/usage/echo.rst | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/doc/usage/echo.rst')
-rw-r--r-- | roms/u-boot/doc/usage/echo.rst | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/roms/u-boot/doc/usage/echo.rst b/roms/u-boot/doc/usage/echo.rst new file mode 100644 index 000000000..861abdfd1 --- /dev/null +++ b/roms/u-boot/doc/usage/echo.rst @@ -0,0 +1,65 @@ +echo command +============ + +Synopsis +-------- + +:: + + echo [-n] [args ...] + +Description +----------- + +The echo command prints its arguments to the console separated by spaces. + +-n + Do not print a line feed after the last argument. + +args + Arguments to be printed. The arguments are evaluated before being passed to + the command. + +Examples +-------- + +Strings are parsed before the arguments are passed to the echo command: + +:: + + => echo "a" 'b' c + a b c + => + +Observe how variables included in strings are handled: + +:: + + => setenv var X; echo "a)" ${var} 'b)' '${var}' c) ${var} + a) X b) ${var} c) X + => + + +-n suppresses the line feed: + +:: + + => echo -n 1 2 3; echo a b c + 1 2 3a b c + => echo -n 1 2 3 + 1 2 3=> + +A more complex example: + +:: + + => for i in a b c; do for j in 1 2 3; do echo -n "${i}${j}, "; done; echo; done; + a1, a2, a3, + b1, b2, b3, + c1, c2, c3, + => + +Return value +------------ + +The return value $? is always set to 0 (true). |